C04B - INSTALLATION GUIDE - INSTALLATION

C04B-1 Carpet and Cushion Installation - General Requirements
C04B-2 Installation of Carpet Cushion
C04B-3 Installation of Stretch-In Carpet
C04B-4 Installation of Direct Glue-Down Carpet
C04B-5 Installation of Double Glue-Down Carpet (over cushion)
C04B-6 Application of Adhesives
C04B-7 Installation of Patterned Carpet (Stretch-In or Glue-Down)
C04B-8 Installation of Carpet on Stairs
C04B-9 Installation of Wall Carpet
C04B-10 Installation of Other Carpet Types
C04B-11 Installation of Carpet Tiles (Modules)
C04B-12 Installation of Bases
C04B-13 Installation of Outdoor Carpet and Synthetic Turf
C04B-14 Completion of Installation Work
C04B-15 Protection of Carpet Installations
C04B-16 Problems After Installation
Preface:
This study guide covers the installation of carpet and related materials in residential, commercial, and institutional applications to the extent noted for each. Specifiers and other persons using this guide should verify all facts relative to the particular project requirements.

1 • CARPET AND CUSHION INSTALLATION - GENERAL REQUIREMENTS
.01 General:

  • The installation of carpet flooring shall be governed by the scope of work (including work included and excluded) as noted in Part C04A - Scope of Work unless otherwise defined under by trade agreements within the area of jurisdiction of the work.

  • The materials, equipment, and services required to supply and install carpet flooring shall be governed by the requirements noted in Part C of the Carpet Flooring section of the NFCA Manual.

  • Regardless of the installation method chosen, proper preparation and the use of skilled installers is necessary for a satisfactory finished appearance and the performance of carpet, cushion, and related accessories.

  • Most carpet floor covering contractors employ highly skilled installers who recognize the importance of following proper procedures to assure both the best appearance and the best performance of the finished installation. This means careful attention must be given to the proper preparation of substrates, a properly planned installation layout to assure colour and pattern match, pre-conditioning of carpet and cushion, and finally the use of a correct installation procedures and techniques. The carpet manufacturer's recommended installation procedures must be followed or the manufacturer will reserve the right to withhold any guarantee unless there is rigid adherence to such procedures.

  • Part of any installation is the correct choice of appropriate materials to suit both the project design requirements and the actual site conditions.

  • Prior to installation the carpet manufacturer (and the cushion and adhesive manufacturers when applicable) must be consulted in regard to the suitability of and recommendations for their flooring materials and methods of installations in both stretch-in and glue down carpet and cushion installations. Only methods and materials specifically designed for the materials and installation methods selected shall be used.
.02    Tools and Installation Materials:

  • All carpet, cushion, and accessories shall be installed using tools and materials recommended by the material manufacturers and as referenced in this standard.

  • Proper tools and use of appropriate materials are essential for skilled and proficient carpet installation.

  • All required tools should be on the job site during the complete duration of installation work to assure a uniform and correct installation. Refer to Part CC1D – Glossary – Carpet Tools for types of tools that may be used.
.03 Acceptable Substrates and Site Conditions:
  • Refer to Part A10 - Acceptable Conditions, for acceptable substrate types and environmental conditions for the installation of carpet materials.

  • Unless otherwise specified or agreed to prior to Bidding or installation, the General Contractor or Owner is responsible for providing acceptable substrates and site conditions for the installation of carpet and related materials.
  • All site and substrate surface conditions and their preparation shall be in accordance with floor covering material manufacturer's recommendations and NFCA requirements as noted in Part A10 - Acceptable Conditions.

    Note: Carpet, when bonded with an adhesive, follows every contour of a substrate, essentially forming a skin. Seemingly insignificant imperfections on a substrate surface can become very obvious after the carpet is installed. Joints, cracks, depressions, and protrusions that are not on an even, level plane may be visible and unsightly in newly installed carpet and cause premature wear. As well, soil, dust, wax, oil, grease, moisture, and other contaminants on the substrate can prevent or otherwise destroy adhesion causing localized or widespread failure.

  • All concrete substrate surfaces shall be tested for moisture and alkalinity in accordance with floor covering material manufacturer's recommendations and NFCA requirements as noted in the Part A11 - Substrate Testing. All other substrate surfaces shall be tested for moisture as required to these noted requirements.

  • All site conditions, installation requirements, and timetable for work shall be reviewed. Substrates, environmental conditions, and work by other trades shall be acceptable prior to commencing any installation of carpet and to ensure that the schedule for installing such materials can be maintained.

  • Any existing carpet or other existing floor covering materials, including adhesives, shall be removed and disposed of in a legal manner or recycled where possible.

  • Carpet shall only be installed over substrates that are acceptable to and are prepared in accordance with NFCA requirements and specific product manufacturers recommendations for the type of flooring materials and specific installation methods selected. Substrates shall be in accordance with following requirements so as to not compromise the carpet or its intended use, and to prevent accelerated wear.

  • All substrate surfaces to receive carpet shall be structurally sound, clean, dry, smooth and free from adhesive, paint, varnish, oils, waxes, sealers and curing and hardening compounds, and any other substances detrimental to filler and adhesive bond. Surfaces shall be vacuumed clean. Note that the use of any cleaning agents, such as sweeping and cleaning compounds, shall be pre-approved by the adhesive and cushion or carpet manufacturers before use.

  • All cracks and protrusions shall be filled or levelled and all indentations and joints must be properly patched or repaired.

  • Where used, patching compounds must be polymer-fortified, suitable for the intended application, and be applied in strict accordance with the patching material manufacturer's instructions and NFCA requirements noted in Part A13 - Patching and Filling.

  • If required by the patch or adhesive manufacturer, patched areas shall be primed, particularly if they are porous and highly alkaline, which may prevent adequate adhesive bond.

  • Substrate surfaces shall be sealed and/or primed if required by the adhesive, cushion, and carpet manufacturer, using materials and methods acceptable to them.

  • Adequate measures shall be taken to protect the face of doors, door frames, and walls from marring due to movement and installation of cushion and carpet and/or removal of existing floor covering materials.

  • All defects likely to impair finished work shall be reported to the General Contractor, Consultant, and Owner in writing. Carpet installation work shall not proceed until all deficiencies and unsatisfactory environmental and site conditions have been corrected.

  • Installing carpet prematurely before other trades have completed their work or in the presence of personnel not essential to the installation of carpet and cushion often results in visible damage, soiling, adhesive failure, delamination, and dimensional instability. These conditions may not be immediately evident.
.04 Planning and Layout:

  • All facets of carpet and cushion installation shall be carefully coordinated before ordering materials.

  • To aid in the estimation / Bidding and ordering / installation of carpet materials, correct measurements, detailed diagrams and cut lists are necessary.

  • In large scale installations, scaled drawings should be prepared using actual site measurements for both new construction or existing areas in order to determine quantities and types of materials to be installed including carpet, cushion, adhesive, mouldings and other accessories, the quantity of carpet per dye lot, and to identify proper location of seams.

  • The following shall also be considered:

    • Seam locations in each area, with seams kept to a minimum.

    • Pile direction in each area.

    • Pattern matching in each area.

    • Quantities of carpet needed for each area, including roll length requirements based generally on the following:

      • Allowing a minimum of 75 mm (3") on each length cut.
      • Allowing a minimum of 75 mm (3") on each width cut.
      • The type of pattern match and repeat and the measurements between a pattern design and repeat.

    • Use of excess material in each area and if and how it will be used without resorting to piecemeal installations. Patchwork is not permitted!

  • Refer to seam, pile direction, and pattern matching requirements below.
.05 Shop Drawings (installation / seam layout drawings):

Do not scale the design authority's drawings or calculate sizes from drawing dimensions shown. All measurements must be taken at the site.

  • Unless otherwise specified, the carpet supplier / contractor shall provide material ordering / shop drawings to the design authority or Owner for pre-approval (in accordance with specification submittal requirements where applicable).

  • Shop (installation / seam layout) drawings shall be prepared for each floor area to be carpeted with each area measured individually, as a basis of supplying, cutting, and seaming the carpet.

  • Shop (installation / seam layout) drawings shall contain the following information:

    • Room and floor numbers (based on drawing information and Finish Schedules provided by the design authority when applicable).

    • Type of substrate, floor preparation required, and installation method for each area.

    • Type of carpet cushion required for each area, including roll length requirements, i.e., a cut list.

    • Type and colour / pattern of carpet for each area, including notations where dye lot and pattern direction changes will occur.

    • Carpet seam layout and pile direction for each area.

    • Quantities of carpet required for each area, including roll length requirements, i.e., a cut and roll sequence list.

    • Excess material in each area and where it will be used (patchwork excluded).

    • Large scale detail drawings where required (carpeted stairs, carpet bases, etc.).

    • Location and type of all edge mouldings and door terminations.

    • Type of base in each area.

  • Shop (installation / seam layout) drawings shall also include the following additional information as appropriate:

    • Name and address of the project (building).

    • Name, address, and phone numbers of the Owner.

    • In new or renovation construction, the name, address, and phone, facsimile, and email numbers of the design authority (e.g. architectural or interior design firm) and the General Contractor or Project Manager.

    • Name, address, and phone, facsimile, and email numbers of the carpet supplier and installation company.

    • Date of drawing and scale

    • Party responsible for removing furniture and oversize items in existing areas

    • Party responsible for removing and disposal of existing floor covering materials in existing areas.

    • Party responsible for preparation of substrate if beyond scope of work requirements. This may include removal of existing materials and slab preparation, underlayments, etc.
.06 Seams:

  • Carpet (and cushion) layouts shall be so designed and installed to keep seams at a minimum and be positioned so that where possible:

    • Seams run the length of the area.

    • Main traffic runs along, rather than across seams.

    • Incident light does not strike across seams.

    • Seams are away from areas subject to pivoting traffic.

    • Seams are not perpendicular to doorway openings.

  • All seams shall be full width of the carpet and end seams of in-fills shall be no less than 900 mm (36") apart.

  • Patchwork is not permitted. Refer also to Planning and Layout
.07 Pile Direction:

  • Where two or more pieces of the same carpet are joined or seamed, the pile direction shall be the same as in other areas unless otherwise specified.

  • All cut carpet for use as field pieces should be marked to indicate pile direction before the arrows or selvedge yarn has been removed.

  • Ideally, pile direction shall be toward the entrance; but other factors, such as pattern, aesthetics, and economic use of material, may also be considered. Where such is the case it shall be reviewed with the design authority before ordering materials and before proceeding with installation.

  • Pile direction on stairs shall be parallel to the run or length of the stair and with pile nap laid from the riser toward the nosing or facing down the stair.
.08 Patterned Carpet and Pattern Matching: (General Considerations)

Note: These manufacturing variations may be adjusted by stretching the carpet if the variations are within the manufacturer's tolerances.

Where the variations exceed the manufacturer's tolerances, the carpet installation work shall be stopped and the manufacturer's representative shall be contacted for specific directions or a resolution.

  • Successful installation of patterned carpet, i.e., matching of carpet pattern or design in adjacent widths or in successive roll lengths to present an uninterrupted pattern, requires a thorough understanding of its characteristics by all parties concerned (Owner, designer, specifier, and all others that are involved in the selection and installation process).

  • There are two basic types of pattern / design repeats. These are:

    • Drop Match: a carpet pattern or design that continues across the carpet diagonally or at a 45 degree angle to the (side) edge or seam.

    • Set or Side Match: a carpet pattern or design that continues straight across the width of the carpet at right angles to the (side) edge or seam.

  • As carpets are a flexible textile and due to the manufacturing process, patterns / design repeats in a carpet cannot be made to exact specifications. The following manufacturing variations in pattern carpet may be encountered:

    • Pattern Bowing: wavy or crooked pattern lines when viewed across the seams.

    • Pattern Bias or Skewing: squareness of the pattern.

    • Pattern Repeat (or run-off): mismatching or uncorrected pattern variations across the width or along seam lengths.

    • Trueness of Edge: wavy or serpentine pattern lines when looking down the length of the carpet.

  • The carpet manufacturer shall be responsible for providing written installation instructions for pattern carpet before installation that shall include any variations in design / pattern that may be expected, the degree of installed mis-match (if any) considered acceptable, and any guarantees or warranties of pattern match offered.
  • Other factors affecting acceptable pattern matching on the job site can include, the method of installation, the condition and levelness of the substrate, and the type of carpet backing system.

  • Because of the pattern variations that may occur and other factors affecting pattern matching, it is imperative that realistic levels of expectation be clearly agreed upon between all parties (i.e., the Owner, designer, specifier, supplier, installer, and all others that are involved in the selection and installation process) before the carpet is ordered.

  • In addition, the carpet manufacturer's material ordering allowances (for both the type of pattern matching and required overages) and specific installation tolerances shall be clearly understood, communicated, and agreed to by all parties prior to specifying, bidding, ordering and installation of all patterned carpet.

  • Patterned carpet shall only be installed by skilled, responsible, and competent installers experienced in the installation of patterned carpet using power stretchers and methods specified by the carpet manufacturer. Because patterned carpet requires more time and expertise and often additional installation personnel, the cost of installation will be affected.
.09 Storage, Handling, and Delivery:

  • Most carpet manufacturers have high manufacturing standards and stringent inspection procedures for their finished products. Nevertheless, all carpets should be inspected upon delivery and before installation and if any suspected irregularities are noted that might give rise to undesirable visual effects, installation should not proceed until the manufacturer has inspected the carpet and an agreed upon course of action has been established.

  • Carpet, cushion, and related installation materials shall be stored, handled, and delivered in strict accordance with material manufacturer's requirements and in a manner to prevent damage or distortion to the materials and surrounding surfaces.

  • All materials shall be stored in the shop and on site in a secure, climate-controlled, dry space within manufacturer's written temperature and humidity requirements, and adequately protected from dirt, dust, moisture, and other contaminants.

  • Carpet and cushion shall be rolled and wrapped / sealed in wrappings approved by the manufacturer with the type, cushion density or carpet colour and registration numbers clearly marked on each roll and delivered directly to work areas when required. Use only tape to wrap cushion and carpet.

  • Carpet and cushion shall be stored in roll form on racks or in flat bins, singularly in rolls or to a maximum height not to exceed three rolls to prevent crushing of the backing or pile and elevated above on-grade floors. Unless specifically required by the manufacturer, do not store carpet or cushion standing on end, except for such carpet as 1800 mm (6 foot) vinyl backed carpet.

  • All other materials (e.g. adhesives, accessories, etc.) shall be in wrapped / sealed original labelled and unopened containers and stored on flat. Stacking heavy objects on top of rolled goods shall be avoided.

  • Carpet and cushion shall be transported on flat dollies equipped with cradles or by forklifts equipped with booms in a manner that prevents damage and distortion. Bending or folding of individual rolls is not recommended, unless absolutely necessary for delivery purposes. Under no circumstances shall cushion or carpet be left bent or folded and shall, upon arrival at the installation site, be immediately unrolled and allowed to lie flat.

  • Cut cushion and carpet not required for immediate installation shall be re-rolled or stored flat in a manner that will not damage such materials. Under no circumstances shall such materials be draped over anything that creates a crease or be moved to and/or stored in an unconditioned space.
.10 Conditioning:

Note: If the temperature and humidity levels are outside these parameters, the installation must not begin until the heating and ventilation system (and air conditioning system if an option) is operational and the temperature and humidity level reaches the minimum manufacturers and NFCA requirements and is maintained for a minimum of 48 hours before, during, and at least 48 hours after the installation.
  • Carpet, cushion, and adhesive materials shall be conditioned or acclimatized within the area of installation and be adequately protected from soil, dust, moisture, and other contaminants during this time. Where possible the conditioning period shall be for at least 48 hours before installation, or as a minimum at least until the materials reach the installation area temperature and humidity levels.

  • To facilitate conditioning, carpet and cushion shall be unrolled in the area in which they are to be installed prior to actual installation to relax the carpet and cushion to the actual site conditions, to minimize wrinkling and buckling, and to permit some off-gassing, within material manufacturer's time limits and conditions. To facilitate relaxation, pre-cutting of the carpet and cushion is recommended.

  • Failure to unroll and acclimatize carpet (and cushion) may result in:

    • roll-crushing.
    • dimensional changes.
    • delamination.
    • permanent creases.
    • permanent indentation.
    • pile reversal.
    • pattern distortion.
    • development of wrinkles and bubbles over time.
    • lack of adhesion.

  • The area in which carpet materials are to be installed must also be heated and ventilated and the ambient and substrate temperatures and humidity levels must be within the carpet, cushion, and adhesive manufacturers requirements. Unless otherwise specified by the manufacturers the ambient temperature shall be between 18°C to 35°C (65°F to 95°F) and the relative humidity shall be between 10% and 65%. Unless otherwise approved by the manufacturers the minimum substrate (notably concrete) temperature shall be not less than 10°C (50°F).
  • The heating and air conditioning systems in these areas shall be carefully controlled during and after installation so as to maintain the heat and humidity levels at a constant level within the ranges noted.

  • To help exhaust, dissipate and eliminate "new" carpet, cushion, and adhesive lingering odours from the installation area, the ventilation system and/or exhaust fans shall be operated at full capacity for a minimum of 48 to 72 hours, with the air exhausted to the outside and with air re-circulation avoided. Doors and windows shall also be opened if practical and possible to aid in this process.
.11 Cushion Layout and Cutting: (when cushion is used)

The orientation and seam layout of the carpet above shall dictate the orientation of cushion layout and seam locations.
  • The cushion and carpet manufacturer must be consulted in regard to their recommendations for the installation of cushion in both stretch-in and double glue down carpet over cushion installations and the installation of cushion shall be carefully coordinated with carpet installation.
  • Cushion shall be installed on acceptable and prepared substrates in longest continuous lengths possible with seams at right angles to carpet seams or offset at least 150 mm (6") from carpet seams. The use of small pieces of cushion is not recommended as they can move during an installation and can show up as indentations at a later date.

  • Cushion shall be cut after conditioning to cover the area and be trimmed flush with the inside contour of tackless strips (for stretch-in installations) or flush to the wall (for double glue installation with trimming to walls done after adhesive set if desired). All interfaces and seams shall be butted tightly together without compression, gaps, wrinkles, or bumps.

  • Depending on the type of acceptable substrate, cushion shall either be fastened to substrate surfaces using staples (for wood substrates) or a non-flammable adhesive (for concrete and other hard surface substrates) around the perimeter (abutting tackless strips), within high traffic areas, and at the seams, or be loose laid depending on the carpet installation method specified or chosen. Refer to the following stretch-in carpet over cushion or double glue down carpet and cushion requirements indicated below.
.12 Carpet Layout and Cutting:

  • Carpet shall be laid out with consideration to traffic patterns and seam placement, and in accordance with planning and layout, seam locations and pile direction requirements noted herein.

  • Carpet shall be cut after conditioning and, where applicable, after cushion has been installed, in accordance with pre-approved carpet seaming plans allowing a minimum of 75 mm (3") extra for trimming at wall lines and sufficient material for seams and pattern matching requirements.

  • Caution: Carpet shall not be cut over carpet or cushion as this can result in over penetration of the blade and the cutting of cushion or carpet below.

  • Note: Care must be taken to ensure that no loops are cut in all cut/loop and loop constructions. Although "row-cutting" is preferred, other cutting techniques may be more suitable. As many carpets do not lend themselves to all methods of cutting the carpet manufacturer shall be consulted for specific cutting and trimming recommendations.

  • Special Note: Woven carpets should be cut between the rows using a top cutter. Where length-wise cuts in woven carpet are required, the carpet is bent along its length to separate the rows and expose the backing yarns. The pile is parted or traced along the length of the proposed cut and the cut started by making a small incision on the edge with a carpet knife. A top cutter is inserted between the backing yarns and the carpet is cut along the face. The top cutter should always be inserted so that the blade is close to the seam edge. Where width-wise cuts are required, the same procedure is followed, but the top cutter should be inserted with the blade close to the seam edge. All cut edges must be immediately sealed with seam sealer by pressing latex into the base of the pile and backing.

  • Carpet including in-fills in each area shall be cut from the same roll and/or in roll sequence so that carpet colour, pile direction, and pattern match.

  • All carpet cut for use as field pieces should be marked on the backside to indicate pile direction before the arrows or selvage yarn have been removed.

  • When installing patterned carpet, each cut should be sufficient in length to meet pattern matching and trimming requirements. Pattern carpet shall be sequenced and installed in accordance with its pattern count measurement in each area and not in accordance with carpet roll numbers.

  • Carpet breadths or sections shall align in their proper position, and edges to be seamed shall be trimmed to suit. All edges shall be butted tightly together without compression, gaps, wrinkles, or bumps.

  • Refer to additional requirements indicated herein for each type of carpet installation.
.13 Edge Seaming:

Note that the majority of non-patterned woven carpets require selvedge edge trimming prior to seaming, generally on or between the warp yarns on the back of the carpet. The selvedges of some woven carpet however, must not be trimmed. In all cases the carpet manufacturer must be contacted for specific edge seaming recommendations for woven and patterned carpets.

To prevent ravelling or fraying of the face fibres at seams and cut-outs, all non-coated or dry-backed woven carpets must be coated with a latex sealer prior to trimming or cutting.
  • Prior to seaming of carpets in stretch-in and double glue down installations with taped seams, both trimmed edges of carpet sections to be joined must be sealed with an appropriate seam adhesive immediately following trimming yarns to prevent fraying and ravelling at seams. Latex seam sealer or thermoplastic adhesives are acceptable, although the type used must be pre-approved by the carpet manufacturer before use.

  • The seam adhesive must be allowed to thoroughly dry before seam seaming.

  • In direct glue-down installations the seam sealer must be applied to both trimmed edges in a manner that encapsulates both primary and secondary backings without contaminating the carpet face yarns. A 3 mm (1/8") continuous bead of seam adhesive should be applied to the base of the first edge only, that side being the first one placed into the floor adhesive, where the face yarn enters the backing. This will seal the first edge as well as the second when the edges are butted together to form the seam.

  • Failure to properly seal seam edges often results in:

    • edge ravel.
    • edge delamination.
    • loss of face yarns / tuft loss.
    • seam separation.
    • safety concerns.

  • Edges that are to be joined as seams must be carefully trimmed using appropriate tools in strict accordance with manufacturer's recommendations. Sufficient material must be removed or trimmed from the factory edge or selvedge to produce level seams and eliminate possible height variations at the seam.
.14 Seaming:

  • A variety of seaming options exist with the method dictated by the type of carpet backing and carpet construction. In all cases the carpet manufacturer shall be consulted for specific recommendations.
    Note:
    Premium tape with high tensile strength and sufficient adhesive on the woven scrim is recommended. In some critical seaming situations, to minimize elevating and peaking, a 150 mm (6") wide tape should be used.
    The carpet shall be pre-stretched in the seam direction before making the seam.
    The method of hand sewing and the type of stitch used must be in compliance with the carpet manufacturers recommendations for the type of carpet specified.
    The most commonly used stitches for seaming various carpet constructions are the overcast and cross stitches which are generally placed not more than 13 mm (2") apart and not less than 13 mm (2") from the edge of the carpet.
    All stitching shall have a latex coating and tape applied over the stitching.

    • Hot Melt Tape Seaming: This most commonly used seaming method uses a fabric seaming tape pre-coated with a thermoplastic adhesive that is centred beneath the seam. Heat from an electric iron melts the adhesive, laminating the carpet backing to the tape. A grooved iron is recommended for better penetration of the adhesive. Proper iron temperature is essential, with special care taken for carpet with synthetic backing or synthetic pile yarns. Consult tape manufacturer's recommendation for heat settings. Always run the iron in the direction of the pile lay. A heat shield for the iron is required. A metal surface should not be used to weight the seam behind the iron.

    • Tape and Latex Seaming: This seaming method utilizes a fabric tape that is centred directly under the seam, upon which latex seaming adhesive is applied. This wet-seaming procedure produces flat seams but seams must be allowed to dry or cure at least eight (8) hours before the carpet is stretched.
    • Electrical Tape Seaming: This seaming method, using electrically conductive tape, is for conductive carpet installations only and the tape and carpet manufacturer's recommendations must be explicitly followed.

    • Hand Sewn Seaming: This traditional seaming method can be used for most carpets except that it is slow and costly to produce and should only be undertaken by qualified installers fully familiar with this seaming method. Hand sewn seams are strong and sufficiently flexible to stretch with the carpet and are generally recommended for all Wilton and most other woven carpets. Due to the limited amount of woven vs. other types of carpet installed, the demand for hand sewn seams and installers available or capable of doing this skill has been reduced.
  • A properly constructed seam should be nearly invisible and should have the following properties:

    • Have cleanly trimmed edges properly secured with seam sealer.

    • Have tightly abutted edges without gaps or overlaps.

    • Maintain uniform appearance and reasonable pattern match where applicable.
.15 Seam Peaking:

  • One problem encountered during carpet installation is seam peaking of taped seams. This is also known as puckering, pleating, or wrinkling and is a normal and expected response to the physical forces applied during stretch-in carpet installations. The carpet backing absorbs the forces applied until they reach the point where the carpet has been joined together with seaming tape adhered to the carpets secondary backing. As the stretching force is applied along the seam, the seaming tape is pulled upward in an attempt to align itself with the approximate centre of the carpet backing. This creates an elevation or lump in the carpet along the seam which causes the carpet pile to gap open in a V-configuration or peak. This is more evident when light strikes the peaked seam, showing the edge facing toward the light source to appear lighter than the one facing away from it.
  • Slightly less stretch applied to the carpet's width compared to its length usually lessens the tendency for seam-peaking.

  • To minimize seam peaking, the following shall be considered:

    • Seams should be orientated to run into the light source rather than across it. This will minimize shadows that will highlight seams.

    • A wider (i.e., 150 mm (6") tape should be used to allow the stretch to be distributed over a wider surface area. This will not eliminate peaking but will help to dissipate the force and make peaking less distinct if it does occur.

    • To minimize distortion and shrinkage of polymeric carpet backings caused by heat, the temperature setting of the seaming iron must be carefully observed. Any heat shrinkage accentuates seam peaking.

    • All edges must be sealed before seaming using a latex seam sealer applied to the edges and smoothed in with the fingers to allow quicker drying time and to avoid transfer of the sealer to the seaming iron.

    • All carpet edges should be back-rolled prior to applying seam tape to reduce peaking.

    • The carpet should be pre-stretched 1% to 1 1/2% for about 450 mm (18") on both sides of the seam to relieve some of the stress the seaming tape must withstand.

    • Seams should be constructed over a flat, firm surface. If the carpet is installed over soft, low density and/or thick carpet cushion a thin, smooth piece of plywood, hardboard or other similar material should be inserted between the carpet and cushion to provide a firm surface during seaming.

  • Note: Peaked seams will generally flatten in traffic areas following exposure to regular foot traffic. The problem will remain in non-traffic areas.
.16 Fitting:

Note: Some woven carpet selvedges must not be trimmed. Refer to cutting information noted above.
  • Once installed, all carpet (and cushion) edges shall be trimmed using tools and techniques best suited for the carpet style (e.g., loop-pile, cut-pile, cut-and-loop pile, woven, and patterned carpet) and edge condition.

  • Carpet installations must be finished flush along wall lines and other vertical surfaces, leaving a smooth, neat and secure transition. Carpet shall be trimmed without damaging baseboards or mouldings, leaving sufficient material for backing to be securely tucked into the gully without protruding face or backing yarns.

  • Where wall base is already installed, as may be in stretch-in carpet installations, carpet must be trimmed without damaging the base, leaving sufficient material for backing to be securely tucked into the gully without protruding face of backing yarns. Minor scratching of the base surface finish may be unavoidable during this tucking process. Due care and attention shall be taken to limit this.

  • Trim seam edges far enough into the material to maintain the structural integrity of the carpet and to join edges without gaps or overlaps.
.17 Unprotected / Transition Edges:

  • All carpet installations must be neatly finished and securely adhered or fastened along walls and other vertical projection surfaces, and at exposed edges. It is highly recommended that some type of base (e.g., resilient base with toe, wood base or other moulding, ceramic base, or a carpet base) be used to conceal the carpet edge along walls.

  • At transition areas against hard surface flooring (such as hardwood flooring or ceramic tile) where a transition moulding or trim is not used, the carpet edge must be a minimum of 1.5 mm (1/16") lower than the adjacent hard surface to prevent damage to and/or unravelling of the carpet edge.

  • At all other transitions areas of carpet to other floor covering edges, the carpet must be protected with an appropriate transition moulding.

  • Seam sealer shall be applied to the edge of carpet at the transition areas and at edge mouldings to prevent raveling.
.18 Expansion Joints:

  • Expansion joints allow separate floor surfaces to expand and contract independently. Because of this carpet shall not be installed over such joints. This does not include cut or saw joints within a section of the floor.

  • If no expansion joint device or cover is specified or noted on the drawings at such locations, the Designer, Owner, and General Contractor must be made aware that failure to address floor expansion may result in installation failure damage to the carpet and potential safety concerns.

  • Non-stable / unsound substrate joint conditions must be handled in strict compliance with the appropriate architectural drawings.

  • In addition, carpet shall not be installed on any substrate that does not provide a stable and mechanically sound surface.
2 • INSTALLATION OF CARPET CUSHION

.01    Carpet cushion may be used in both stretch-in and in glue down caret installations.

.02    Refer to General Installation Requirements (Cushion Layout and Cutting) above.

.03    Carpet cushion shall be installed free of buckles and wrinkles, with seams at right angles to or at least 150 mm (6") to one side of the carpet seams above, or offset from                  carpet seams by a minimum of 300 mm (12"). Cushion edges shall be neatly butted together and seams taped as noted herein.

.04    Carpet cushion with one or two scrim reinforced faces shall be installed in accordance with manufacturers recommendations. Foam or sponge cushion with a waffle design              should be installed with the smooth side up.

.05    For stretch-in carpet installations:

  • Carpet cushion for stretch-in carpet shall be installed up to edge of tackless strips and be securely fastened to the substrate using staples or non-flammable cushion adhesive at the seams, projections, and 25 to 150 mm (1" to 6") within the perimeter edges all around the installation or where cut to contours to prevent shifting.

  • To prevent shifting of the cushion during and after the carpet installation and to eliminate staining from dust migration all cushion seams (except fibre cushion seams) shall be secured with tape as noted below.

  • Foam cushion seams are to be made using vinyl covered fabric tape or duct tape applied to full-length of seams with 200 to 250 mm (8" to 10") strips of tape placed at right angles to the seam at 460 mm (18") intervals.

  • Felt cushion seams may be sewn with stitches not more than 25 mm (1") apart and at least 25 mm (1") from the seam edges or be taped using tape recommended by the cushion manufacturer.

  • Over wood substrates foam and fibre cushion may also be periodically stapled (stay tacked) to the substrate so that it stays in place during installation of carpet over it.

.06    For glue down carpet and cushion installations:
  • Carpet cushion to be glued to substrates shall be installed up to perimeter wall surfaces and adhered using appropriate adhesive and trowel notch size as recommended by cushion and adhesive manufacturers for type of cushion and substrate surface that applies.

  • Adhesive shall be spread uniformly over substrate surface at coverage rate and within open time specified by adhesive manufacturer.

  • Cushion shall be installed over adhesive and pressed into place using a roller of weight and size specified by cushion manufacturer.

  • For cushion adhesives refer to Application of Adhesives below. Proper open time considerations are critical for a successful cushion installation.
3 • INSTALLATION OF STRETCH-IN CARPET

.01    The stretch-in carpet installation method requires fastening the carpet (usually over a separate cushion) under tension onto tackless strips secured to the substrate around the          perimeter of the area to be carpeted. This method is primarily used in residential applications.

.02    Stretch-in carpet installation may be considered for the following reasons:

  • It provides enhanced underfoot comfort, acoustical properties (i.e., higher noise reduction coefficients and higher impact noise ratings) when installed with separate cushion.
  • It increases thermal insulation (R-value).
  • It can be used over floors that are unsuitable for glue-down.
  • Because patterned carpet may be more easily matched.
  • Corrective measures, such as seam repair, may be easier to perform.
  • Removal costs are usually less than the removal of an adhered installation.

.03    Stretch-in carpet installation should be avoided:
  • On ramps and inclines.
  • Where office systems furniture and demountable partitions are utilized.
  • Where heavy rolling traffic is likely.
  • Where there is excessive humidity.
  • When carpet has a unitary backing or other backing systems designed only for glue-down installation.

.04    Unless otherwise noted herein, all stretch-in carpet shall be stretched in using a power stretcher.

Note:
The use of a power stretcher is mandatory for all installations. This excludes all other stretching devices. Knee kickers and the like shall not be used due to the potential injury to the installer. Other devices used as a substitute for, or an attachment to a power stretcher that penetrates the carpet backing may cause injury, damage the carpet or substrate, or result in inadequate stretch. Such devices shall also not be used.
Note: Failure to power stretch a carpet may result in wrinkling and buckling over time, localized damage to the carpet, and delamination.

.05    The type of tackless strip selected shall be in accordance with the specific type of carpet to be installed and the fasteners and method used shall suit the type substrate.              Refer to Part C04C - Carpet Material Guide for tackless strip types and information.

.06    Commercial or architectural tackless strips with three rows of pins, or two conventional tackless strips with two rows of pins each shall be used for carpet with heavy-latexed              backs, for most woven and Berber-style carpet, and for any carpet in rooms exceeding 9150 mm (30 feet) in any direction (length or width).

.07    Full length pieces of tackless strip shall be placed around the wall perimeter with pins pointing toward the wall and securely attached to maintain the proper stretch provided by          power stretching. A gap or "gully" of slightly less than thickness of the carpet, but not exceeding 10 mm (3/8"), shall be left between the wall and tackless strip. A spacer should          be used to maintain a consistent gap. Tackless strips shall be cut to proper lengths to maintain the same gully, regardless of the shape of the wall.

.08    Tackless strips shall be securely attached to substrates with an acceptable contact adhesive, or be drilled and pinned or nailed to maintain the stretch provided by power                  stretching. A minimum of two fastening points are required for the smallest piece of tackless strip.

         Note: Over radiant heated floors non-prenailed tackless strips shall be glued in place unless the location of pipes or tubing is precisely known (i.e. the locations              must be marked out on the slab surface). This is necessary so that holding nails will not be driven into the conduit or tubing.

.09    Avoid placing tackless strip across door openings or door sills where possible.

.10    To prevent possible injury, the pins on tackless strips must not protrude through the carpet being installed.

.11    The stretched carpet backing shall be hooked onto the tackless strip at the starting walls and on the tackless strips in the surrounding area. In no case shall carpet be stapled             to tackless strips. The type of carpet, floor area covered, and other requirements will govern the stretching method to be used. The method to be used shall be confirmed by              the carpet manufacturer before commencing such work.

.12    Before power stretching, make certain that hot melt tape seams are cool to the touch and latexed seams have dried. Generally a four-way stretch is required. In the absence of          a carpet manufacturer's stretch recommendations refer to the Stretch Diagram for procedures.

.13    Amount of Stretch:

  • Due to the difference in carpet backing types, the carpet manufacturers recommendations for stretch must be followed.

  • Refer to Part CC2A to D for stretch-in installation details for tufted, Wilton, Axminster, and knitted carpets.

  • Unless otherwise required by the carpet manufacturer:

    • tufted carpet with a synthetic secondary back should be stretched 1% to 1 1/2% in width and length.

    • tufted carpet with a jute secondary back should be stretched "drum tight."

    • woven carpet and other constructions should be stretched in accordance with the carpet manufacturer's recommendations for the amount of stretch applied and the method to be used.

  • Wrinkles and buckles are most often caused by failing to adequately stretch a carpet using a power stretcher, using inappropriate cushion, installing carpet under adverse temperature and humidity conditions, or by inadequate conditioning. Slightly less stretch applied to a carpet's width compared to its length usually lessens the tendency for seam peaking.

.14    A wall trimmer shall be used to trim carpet along walls and abutments. The trimmer shall be adjusted to leave enough carpet to tuck carpet edges or ends into the gullies.

.15    Refer also to General Installation Requirements above.

.16    For edges and seams refer to General Requirements above.

4 • INSTALLATION OF DIRECT GLUE-DOWN CARPET

.01    In direct glue-down installations, the carpet is adhered directly to the substrate.

.02    Direct glue down installation may be considered for the following reasons:

  • More suitable for rolling traffic and ramp areas.  Note: carpet manufacturers may or may not require the use of chair protectors under all wheeled chairs.
  • Seams are more durable since there is no vertical flexing.
  • Minimized buckling in buildings that have HVAC systems turned off for extended periods of time.
  • No re-stretch situations.
  • Facilitates access to electrical and telephone lines under floor.
  • Practically eliminates incidences of seam peaking.
  • No restrictions to area size.
  • Intricate border and inlay possibilities.
  • Usually less expensive.

.03    Direct glue installation of patterned carpet may require specialized procedures to obtain an acceptable match.  Consult the manufacturer for specific installation requirements          and possible warranty conditions.

.04    Refer also to General Installation Requirements above.

.05    For adhesives refer to Application of Adhesives below.

.06    For edges and seams refer to General Requirements above.

5 • INSTALLATION OF DOUBLE GLUE-DOWN CARPET (OVER CUSHION)

.01    In double glue-down installation, a separate cushion is adhered to the substrate surface and the carpet is adhered to the cushion using appropriate adhesives. This method              accounts for approximately 10% of carpet installation work.

.02    Double glue down carpet installation may be considered for the following reasons:
  • Combines the stability of direct glue-down carpet with the cushioning benefits of a separate cushion, stretch-in installation.
  • Improves carpet appearance retention, foot comfort, and overall performance.
  • Simplifies carpet bordering and inlaying.
  • Suitable for wheeled traffic areas.
  • No restrictions of size of area.

.03    As significant differences exist in various carpet cushions, consult with the manufacturers of the cushion, carpet, and adhesives for recommendations regarding this method of          installation. Only materials specifically designed for this end use application should be utilized.

.04    Site, environmental, and ventilation conditions become even more important when performing double glue-down installations.

.05    Cushion Layout and Installation: After the substrate has been properly prepared, the cushion shall be laid out and cut in accordance with requirements noted above and              then adhered to the substrate using adhesive and installation methods recommended by the cushion and adhesive manufacturer.

.06    Carpet Layout and Installation: After the cushion has been installed and the adhesive has set, layout and cut the carpet in accordance to requirements noted above and                  spread out in the area to be carpeted. The carpet should be cut 75 to 100 mm (3" to 4") longer than the area measurement. Where applicable, allow for pattern repeat. Carpet          seams should be at a right angle to cushion seams or offset at least 150 mm (6") to either side.  Align all carpet breadths to their proper position and trim seams. Care must              be taken to avoid cutting into the cushion under the seam.

         Seams may be constructed with a special hot melt tape for added protection. This may produce a slight bump at the seam, however the seam will stay together longer.

.07    Refer also to General Installation Requirements above.

.08    For cushion and carpet adhesives refer to Application of Adhesives below.

.09    For edges and seams refer to General Requirements above.

6 • APPLICATION OF ADHESIVES

.01    Refer to General Installation Requirements and Direct Glue Down and Double Glue Down Installations above

.02    Adhesive Types:
  • Cushion, carpet, and carpet seam adhesive shall be as recommended by both the carpet and adhesive manufacturers.
  • Special floor and seam adhesives are required for carpets with PVC backing.
  • Alternate field-applied adhesive systems, such as spray adhesive or roll-adhesive films, may be available. Verify with carpet and cushion manufacturer for acceptability and pre-approval prior to use.
  • For pre-applied adhesive (peel-and-stick) systems, refer to Installation of Other Carpet Types below.
  • Note: Adhesives applied to bare metal surfaces can cause rapid oxidation or other chemical reactions. Bare aluminium must be sanded prior to adhesive application to remove oxidization.

.03    Adhesives and Trowel Notch Sizes:
  • Adhesives: All adhesives used shall be in strict accordance with the cushion and carpet manufacturer and adhesive manufacturer's recommendations.
  • Trowel notching: shall be in accordance with the cushion and carpet manufacturer and adhesive manufacturer's recommendations for materials to be used and substrate type encountered. Rough, porous, concrete surfaces and heavily textured carpet backings may require a trowel with deeper notches than listed.

  • Note: For general guidelines for adhesive types and trowel notch sizes refer to Appendix CC7 – Adhesives and Trowel Notch Sizes.
    • It is important that the trowel notch be large enough to apply a continuous film of adhesive for 100% transfer onto the cushion and into the carpet backing while maintaining full coverage of the floor.
    • As trowel notches wear down during use, the wear should be monitored to ensure that the notch size is maintained.

    .04    Application of Adhesives:
    • Prior to application of any adhesive, all contact surfaces (substrate and cushion) shall be dry and free from contaminants that will prevent good adhesion, and be thoroughly cleaned and vacuumed as required.

    • Adhesives shall be spread uniformly over the entire surface using applicable adhesive, methods and trowel sizes recommended by adhesive and cushion and carpet manufacturers, maintaining proper trowel (notch) size and adhesive spread rates throughout the installation.

    • A 100% transfer of floor adhesive into the cushion and/or carpet backing, including the recesses of the carpet back, while maintaining full coverage of the floor, must be attained.

    • Woven and unitary-backed carpet require full penetration of the adhesive into the valleys or depressions between tuft rows.

    • Caution: Lack of adhesion is most often caused by:
      • improper adhesive selection or quality.
      • incorrect trowel size or configuration.
      • incorrect open time.
      • Inadequate rolling time.
      • residual curing or parting compounds.
      • moisture related problems.
      • premature traffic or cleaning before adhesives have adequately cured.

    • Open Time: Proper open time considerations are critical for a successful glued cushion and carpet installations. Open times will vary depending upon environmental conditions and the adhesive type used. The amount of humidity in the area greatly affects open times with higher humidity requiring a longer time. Squirrel cage fans may be used to help the adhesive set faster. Some cushion as well as carpet backing types will not absorb adhesive quickly and will require more open time for the adhesive to become tacky. If the space is air conditioned, the unit should be turned on in summer or the heat should be turned up in the winter to reduce humidity to below 65%.
    • Installing cushion or carpet before the adhesive has reached a "tacky" stage will result in installation failure.
      • After sufficient open time, the cushion and/or carpet should be pressed into the adhesive and rolled with the appropriate roller.

      • For edges and seams refer to general requirements above.

      .05    Sprayed Applied Adhesives:
      • The use of sprayed applied adhesive is usually restricted to the application of a tack coat for certain types of carpet but may also be used in some instances to hold a cushion in place under stretch-in carpet over cushion in large areas, to stop the cushion from wrinkling.

      • Whereas the use of spray may be a quicker method of application, there are a number of disadvantages:
        • Restricted to certain types of carpets / carpet backings.

        • The substrate must be sanded to eliminate surface imperfections and depending on the type of surface may have to be sanded to provide a surface acceptable for application of the adhesive. Sanded surfaces must be vacuumed clean prior to application of the adhesive.

        • The spray applicator cannot "feel" any irregularities in the substrate surface that may be felt when applying adhesive with a trowel.

      • Areas must be free of dust, wax, oil, grease, etc. and alkaline and moisture free.

      • The carpet and/or special pad shall be laid out in conventional manner. In a replacement stretch-in application, the tackless does not have to be removed. New cushion can be fit up to it and the new carpet stretched over it. All seams must be sealed.

      • Sprayed Adhesive Application Procedures:

        • Sprayer head should be 200 to 250 mm (8" to 10") from floor in position perpendicular to the floor.
        • Lapping of sprayed areas should not exceed 50%.
        • Release trigger at end of stroke so as to eliminate adhesive build-up.
        • Use of a guard or covering is necessary to protect walls and fixtures.
        • Keep sprayer head in a container of water when not in use; this prevents clogging of nozzle.
        • Carpet cross seams require adhesive to be applied to substrate and/or cushion and carpet backing to ensure a well bonded and tight seam.
        • Spray method can be used for tile installation. Open or to set up time would differ from broadloom installations. (Refer to manufacturer's recommendations before applying).
        • Carpet must be rolled in both length and width directions using a roller of weight recommended by the carpet manufacturer.
        • Upon completion, check for bubbles and any clean up of adhesive on walls, fixtures, etc.

      .06    Rolling:
      • After sufficient adhesive open time, glued down carpet or cushion must be pressed into the adhesive and rolled with the lightest roller that will achieve 100% transfer of the floor adhesive into the carpet back or cushion, including penetration into the backing's deepest recesses and a complete bond to substrate. The carpet or cushion shall be rolled in both directions until a full bond has been achieved and should not be roll excessively beyond this point.

      • Refer to the carpet and cushion manufacturer's recommendations for roller weight.

      • The type of carpet also dictates rolling methods and requirements:

        • Jute or Synthetic Secondary Backing: Tufted carpet with jute or synthetic secondary backing should be pressed into the adhesive bed using a section of carpet core or a roller. Roll in both directions and do not over roll.

        • Unitary and Woven Carpet: Unitary carpet and woven carpet must be rolled a second time about 3 to 12 hours after initial rolling to make sure a strong bond is established.
      • All seamed edges should be rolled according to carpet manufacturer's recommendations.
7 • INSTALLATION OF PATTERNED CARPET (STRETCH-IN OR GLUE DOWN)

.01    Generally, patterned carpet can be installed by all installation methods. The carpet manufacturer shall be consulted for specific recommendations for the type and pattern of              carpet to be installed and for any restrictions.

.02    Refer to General Installation Requirements for carpet and cushion noted herein.

.03    Patterned carpet must be laid out according to the seaming diagram, which must reflect the desired pattern direction and balance within the area of installation.

.04    Rolls of patterned carpet must be sequenced so the longest pattern is installed first and the roll with the next longest pattern can be stretched to match the longer one. This              procedure is critical in that it is impossible to shrink a longer pattern to match a shorter pattern. This will require that each roll be measured for pattern repeat prior to                          installation.

         Roll sequencing information shall be provided by the carpet manufacturer. .05

         Sequence carpet cuts working from the longest measured repeat gradually down to the shortest repeat within the dye lot.

.06    After preconditioning and before cutting and installation, the installer shall check bow, skew and pattern elongation. Measurements obtained shall not exceed the carpet                      manufacturers written requirements and the following minimum tolerances, whichever is less. Where they do, the Work shall stop and the carpet manufacturer shall be notified          immediately.

  • Bow Tolerance: in accordance with manufacturer's specification tolerances but not greater than 38 mm (1 1/2") in 3660 mm (144") width or length.

  • Skew or Squareness of Pattern: in accordance with manufacturer's specification tolerances but not greater than 38 mm (1 1/2") in 3660 mm (144") width.

  • Pattern Repeat / Run-Off: in accordance with manufacturer's specification tolerances but not greater than 25 mm (1") in 3120 mm (120") length.
Note: All manufacturers do not use the same tolerances. The Canadian Carpet Institute does however have a standard for carpet pattern variations. Each pattern type will possess different characteristics and consideration must be allowed for each type. If unknown, check with the carpet manufacturer for specifics.

.07    The installer must measure and define the exact pattern match before beginning the installation. The exact pattern match may vary slightly from the match stated in the                      product specifications.

.08    Variations in pattern shall be determined from a single uninstalled breadth of carpet as follows:
  • Pattern Bow: Bow occurs when a pattern runs off in a curved line across the width of a carpet roll. To measure bow, stretch a string across the width of the carpet from match point on one side to the corresponding match point on the opposite side. These reference points should be as close to the selvage as possible. Measure the distance of greatest separation between the string and the pattern line. Uncorrected pattern bow is visible on the floor as wavy or crooked pattern lines when viewed across the seams. Refer to Part CC2E, Fig. 1 and 3 for details.

  • Bias or Skew: This describes the squareness of the pattern. Bias or skew occurs when the pattern runs off in a straight line at an angle across the width of a carpet roll. This condition is measured using one of the methods described below.

    • Diagonal Difference Method: Refer to Part CC2E, Fig. 2 and 4 for details.
    • Step 1: Take the same two pattern points previously identified in the pattern bow measurement and mark with masking tape or white chalk as A and B.


      Step 2: Using a steel tape, measure exactly 9 feet from these points parallel to the selvage, allowing the steel tape to follow the same length pattern line. These points should also be marked with tape or white chalk as C and D.

      Step 3: Measure diagonally from A to C and from B to D as indicated. If diagonals are equal, the pattern is perfectly square. The degree of inequality indicated severity of bias.

      • T-Square Method:
      • Step 1: Using a 4 foot T-square or long carpenter square, align the short edge of the square along one selvage edge.

        Step 2: Making sure the square's short side is perfectly parallel to the carpet pattern, place one end of a white chalk line at the corner of the square.

        Step 3: Pull the chalk line tight and make sure it stays parallel to the long side of the square.

        Step 4: Follow the pattern and line across the carpet width. The difference between the pattern and line will be the amount of skew or bias. On a job site, uncorrected bias is visible as the pattern running parallel with two opposing walls and running into or away from the other two walls.



    • Repeat Variation (Length): This variation is sometimes referred to as "pattern run off" or "hook" and occurs when a pattern runs off in the last 600 mm (24") down the length of a carpet roll. This is determined by a direct measurement method as follows. Refer to Part CC2E, Fig. 5 for details.
    • Step 1: Determine specified length pattern repeat in millimetres or inches.

      Step 2: Divide this number into 144". This usually results in a whole number. Example, if a carpet is specified as having an 450 mm (18") match, determine the number of repeats in 12 ft (144 inches) by dividing 144 by 18, which equals 8. Use this number (in this example "8") and go to step 3.

      Step 3: Measure the distance covered by this number of repeats in numerous places through the dye lot.

      Step 4: Use these numbers to sequences cuts working from longest repeat (largest number) gradually down to the shortest repeat within the dye lot. Uncorrected pattern variation (width or length) is visible on a job site as seam mismatch.

      Width pattern repeat variation can be determined in the same manner. From an installation standpoint, this is important only on end-to-end or "cross" seams.

      • Trueness of Edge: To measure, stretch a string or white chalk line, at least 40 feet long if possible or as specified by manufacturer, near the selvedge of the carpet. Both ends of the tightly stretched string should be on the same point in the pattern. Trueness of edge is the maximum separation or distance between the string and the pattern line. Refer to Part CC2E, Fig. 3 for details.
      • Uncorrected variation in edge trueness is visible on the job site as wavy or serpentine pattern lines when looking down the length of the carpet.



      .09    Match the pattern at the midpoint of the seam's length working from the seam's midpoint to the seam ends. Bring the pattern into register to achieve proper pattern match at              seams and ensure alignment along walls using appropriate tools. The use of a power stretcher, stay-nails, and a "dead-man" may be necessary.

      .10    Care must also be exercised to ensure pattern alignment along the walls. The use of a power stretcher, stay-nails, and a dead man may be necessary to achieve proper                  pattern matching at seams and alignment along walls.

8 • INSTALLATION OF CARPET ON STAIRS

.01    Carpet on stairs is normally stretched in over cushion but may also be installed by double glue down method.  Carpet can also be directly glued down to stairs without cushion          but due to pre-mature carpet wear this method is not generally recommended.

.02    Carpet shall be installed with the carpet length parallel to the run or length of the stair and with pile nap laid from the riser toward the nosing or facing down the stair. The                  carpet shall be properly secured to stair treads and risers using appropriate fasteners or adhesive.

.03    All bull nose or waterfall stair nosings and returns must be rounded from 19 to 25 mm (3/4" to 1") to prevent sharp stair edges from cutting into carpet and/or cushion, and to              provide proper carpet contact for adhesive installations.

.04    When carpet is installed over cushion the cushion must extend over the stair nosing.

.05    For glued down carpet installation on stairs.
  • On stairs with a return or nosing (i.e., bull nosed or cap and band stairs), the carpet should be cut and installed using separate tread and riser pieces.

  • On stairs without a nosing (i.e., waterfall or nose-less stairs) install carpet in a continuous length, i.e., in one piece, over treads and risers. The carpet shall be stretched at each tread and then tightly secured to treads and risers, using the proper adhesive.

.06    For stretch-in carpet installation on stairs:
  • On stairs with a return or nosing, install a tackless strip on each tread with the pins pointing toward the riser.

  • On stairs without a nosing (i.e., a waterfall or nose-less stair) install a tackless strip on risers with pins pointing down to the tread, in addition to tackless strip on the treads with pins pointing toward the riser.  The gully between the strips is slightly less than double the carpet thickness.  Tackless strips and cushion shall be about 38 mm (1 1/2") less than the carpet width, to allow for a turn under on each side of the stairs.

  • On wide stairs (over 1800 mm (72") provide a tackless strip on stair sides to maintain the proper tension.

  • When using a cap-and-band or upholstered technique, tackless strip is not used on risers.

  • Install carpet cushion to fit net to tackless strips and side walls and hold in place using staples for wood substrates or adhesive for concrete substrates.

  • Cut carpet in one continuous length to fit stair components and width to fit tightly between stair sides (walls / stringers) without gaps or buckles.

  • The carpet shall be tightly stretched over each step and then secured to each tackless strip and forced into the gully with a stair tool at the junction of the tread and riser.

  • Curved or sloped areas shall have the carpet tailored to fit the tread and riser without wrinkles and with edges neatly finished.

  • When staples are used in upholstering carpets on stairs, care must be taken to separate pile yarns to avoid trapping yarns, resulting in visible distortion.
9 • INSTALLATION OF WALL CARPET

.01    The type of carpet selected and associated materials to be used (adhesive, trim, etc.) must specifically meet Code rating requirements for wall coverings.

.02    Acceptable substrate conditions shall conform to carpet manufacturer's requirements. Gypsum board substrates shall be suitably taped, filled, sanded, and sealed and all                  existing wall coverings such as vinyl covering shall be removed. All substrate surfaces shall be suitably prepared, and the adhesive and installation method chosen shall be in          strict accordance with carpet manufacturer's specific requirements.

.03    A plumb line shall be used to establish vertical reference guides for seam layout and a level shall be used to ensure a consistently level top edge.

.04    Carpet shall be wrapped around outside corners and columns with seams a minimum of 300 mm (12") from corners. Carpet installed short of corners shall have suitable                  moulding / trim applied over exposed edges.

.05    Seams shall be trace / double cut depending on the type of wall and finished in accordance with the carpet manufacturers recommendations.

         Note: Some wall carpet requires seam sealing; others do not.

.06    A hand roller shall be used to ensure bubble-free surfaces and that the carpet is fully embedded into the adhesive applied to the wall. The installation shall be periodically                  checked while the adhesive is curing to ensure full contact and that there is no slippage. Any bubbles or peaked seams shall be re-rolled.
10 • INSTALLATION OF OTHER CARPET TYPES

.01    Refer to General Installation Requirements above.

.02    Consult the carpet manufacturer for recommended installation procedures for each of the following carpet types.

.03    Use only floor adhesives and carpet seam adhesives recommend by the carpet and adhesive manufacturer for each of the following carpet types.

.04    Carpet with Attached Cushion: High-density polyurethane, polyvinyl chloride (PVC), or latex gel cushion permanently bonded to the carpet back should be installed as direct          glue-down carpet. The carpet should either be rolled or be pressed into the adhesive with a stiff bristled push broom following installation in accordance with carpet                          manufacturers requirements.

.05    Carpet with Pre-Applied (Peel and Stick) Adhesive Systems: Pressure sensitive adhesives are sometimes applied to polyurethane and PVC attached cushion backings              during the manufacturing process and covered with a peel-off film. Backings of this type have special floor preparation requirements.

.06    Hook and Loop Technology: This is a specialized installation system that utilizes hooked tape and a looped fabric to cover the entire underside of the carpet. This system              involves detailed and specific installation practices.

.07    Carpet over Carpet: In the absence of manufacturer's specific recommendations to the contrary, carpet should not be installed over existing carpet.

.08    Unitary Backed Carpet over Cushion: In the absence of specific instructions from the manufacturer to the contrary, unitary backed carpet should not be installed over a                  separate cushion.
11 • INSTALLATION OF CARPET TILE (MODULES)

.01    Refer to General Installation Requirements above.

.02    The carpet manufacturer's recommendations regarding application, squareness, and location of working chalk lines must be followed precisely.

.03    Layout: Unless otherwise specified or indicated on drawings carpet tile shall be installed in a square 90 degree format with corners aligned in accordance with manufacturer's          specification, working out from quadrant centre line of the area or room, keeping cuts and waste to a minimum, and maintaining straight seams and direction of carpet tile                  pattern.

         Carpet tile pile or nap may be either laid in one direction or in an alternating pattern within any one area as selected by the Consultant subject to a sample area review by the          Owner.

         The quadrant centre lines of the room shall be determined using standard tile layout method as follows. Determine the starting point and snap a chalk line across the room in          both directions through the center to divide the room into four squared sections.

.04    Adhesive Application: The carpet manufacturer's recommendations in regard to type and usage of adhesive shall be followed. Generally, a thin film of pressure sensitive              adhesive is used to prevent lateral movement of modules.

         Typically adhesive is applied in strips at least 930 mm (9") wide using a twist textured paint roller on both sides of each chalk line. When the adhesive is dry or tacky, begin              installing each section into pyramid fashion starting from the centre and working outward.

.05    Peel and Stick Application: Install carpet tile with pressure sensitive adhesive backing by removing the peel-off film and install as noted above or below.

         Additional carpet modules within the quadrant can be installed using the "stair step" technique. In this technique, the tile area grows steadily away from the centre of the room.          Instead of following either of the chalk lines, follow the imaginary diagonal line between them. The installation continues to grow from the centre to the corner of the room                  finishing the entire quadrant before starting the next quadrant.

.06    Joints: Modules in the completed installation must be snugly joined together. Continually check that modules are being placed together with correct firmness. To check for              correct snugness, measure the distance covered by 11 installed modules (10 joints). This distance should be in compliance with manufacturer's specifications for the particular          product being installed. Care must be taken to not trap yarn between modules.

.07    Control Grid: Throughout the installation, a controlled grid should be installed at regular intervals recommended by the carpet manufacturer to keep the tiles from shifting. A              controlled grid consists of a row of modules anchored in place with the same adhesive used to align the centre line tiles. This strip of adhesive should be approximately 4500              mm (15 feet) from the centre line adhesive. Adhesive must always be placed around the perimeter of the area.

.08    Wheeled traffic: Wherever such traffic (from wheeled chairs, equipment dolleys, etc.) will be present, the entire area of carpet tile must installed with adhesive.

12 • INSTALLATION OF BASES

.01    Ensure that wall area is free of surface defects, dust and any other contaminates

.02    Various base types may be installed with carpet. These include:
  • resilient coved or straight vinyl or rubber base.
  • wood base.
  • ceramic tile base.
  • carpet base.

.03    All bases shall be installed in maximum continuous lengths to prepared wall surfaces to locations and heights indicated on the Finish Schedule or drawings straight and level,          and fitted tightly to wall surfaces and other projections. Adjoining lengths shall be neatly fitted and butted to form tight joints and to provide a uniform height.

.04    When carpet or resilient bases are to be adhered to wall surfaces apply adhesive to achieve 100% coverage and set base tightly against the wall and roll base to ensure full              contact with the wall surface.

.05    Unless pre-formed inside and outside corners are used, install one side of resilient base to fit contour of inside corner and cope lip at 45 degrees and neatly fit of other side of          base at inside corners. Back groove base to fit outside corners, apply contact adhesive to wall and back of base, and tightly wrap around the corner at outside corners.

         If specified, install pre-moulded resilient outside corners prior to length pieces, and neatly fit length pieces of base to pre-moulded corner pieces.

         All base joints shall be flush and tight and tops of adjoining pieces shall be level and aligned.

.06    Where carpet is used as a base the top of carpet shall finished or be concealed with a continuous base cap or other trim as selected by the Owner or designer.

13 • INSTALLATION OF OUTDOOR CARPET AND SYNTHETIC TURF

.01    Outdoor carpet and synthetic turf installations offer conditions quite different from those encountered indoors. Both carpet / turf and adhesive are subjected to extremes of                  weather and traffic, and installation surfaces will be much more varied and often uneven.

         Note: The installation of artificial turf on athletic fields is a highly specialized procedure and is outside the scope of this Reference Manual. Consult with the manufacturer for          specific installation requirements and instructions.

.02    Carpet Selection: Carpet to be installed outdoors should be of a construction and type of synthetic face yarns and backing that is recommended specifically for outdoor use.

.03    Carpet Backing: The type of backing material selected is crucial in the installation of outdoor carpet. Outdoor carpet backings are classified as follows:
  • Fabric or Fibrous: woven or non-woven polypropylene backing.
  • Vinyl: unitary or foam backing (requires special adhesive for vinyl).
  • Polyurethane: unitary or foam smooth pattern backing.
  • Latex Rubber: smooth foam waffle and diamond shaped backing.

.04    Carpet Adhesives: Adhesive selection for outdoor carpet installation is very important. Carpet backing and substrate must be compatible with adhesive. The recommended              adhesives for outdoor installations are as follows:
  • Solvent Based Adhesive: Also referred to as all-weather carpet adhesive. Preferred for outdoor installations, as these adhesives can be applied in a wide range of weather conditions and are generally water resistant. Some contain flammable solvents and should only be used outdoors. Consult manufacturer for recommendations.

  • Latex (Water) Based Adhesive: Must be premium quality formulated for outdoor use. Avoid application under damp, humid, or extreme cold or hot conditions. The substrate surface must also be compatible with this adhesive.
         Caution: Regardless of type, some adhesives may not be compatible with all carpet backings.

         Note: The use of the correct adhesive will greatly determine the success of an outdoor installation. When the backing material is unknown, or if doubt exists, contact the carpet          manufacturer for a positive identification.

.05    Environmental Conditions: Temperatures and humidity levels during installation must be within manufacturer's written limits and be no less than 13°C (55°F) or more than              35°C (95°F) and a relative humidity level between 10 to 65%.

.06    Site and Substrate Conditions: All installation surfaces must be sound, smooth, clean, dry, and have adequate drainage. The following additional requirements and                          conditions are important:
  • Concrete Substrates: These surfaces must be cured and be free from excessive alkali. All wax must be removed, and painted surfaces should be sanded thoroughly and cleaned before installation.
  • Wood Substrates: Painted wood surfaces should be roughened prior to installation. Slotted wood surfaces should be covered with an outdoor grade plywood and primed with a primer compatible with the selected adhesive. Waxed or oiled wood surfaces present special problems and will require resurfacing. Adhesive installations over pressure treated lumber are not recommended.
  • Metal Substrates: These surfaces must be free of grease, oil, dirt, and rust and must be properly primed. Painted metal surfaces must be rough-sanded, with loose paint removed.
  • Terrazzo, Ceramic, and Marble Substrates: These surfaces must be clean and all finishes must be removed.
  • Slate and Brick Substrates: These surfaces may be too rough and uneven for most outdoor installations and may require refinishing and levelling before installation.
  • Asphalt Substrates: These surfaces must be free from excessive oil and grease, and in good condition. New asphalt must be cured for at least 30 days, or longer, depending upon weather conditions. Old asphalt may require resurfacing before installing carpet.
  • Swimming Pools Substrates: Regardless of the surface encountered, indoor swimming pools should be drained and dry before installing outdoor carpet. Outdoor pools must not be used during installation. Any fungus or algae must be removed from the surfaces to be covered. Indoor pool areas must be ventilated, to reduce excess humidity

.07    Layout: All outdoor carpet must be unrolled and allowed to relax at least one hour before installation within environmental conditions previously noted.

         The carpet should be pre-cut for the area to be covered, allowing for any required trimming. Seams should be kept to a minimum and run with the traffic pattern when possible.          Knee-kickers may be used to position the carpet properly, but should be used with caution. Where seams are required, be certain that the pile lay runs in the same direction on          both sides of the seam.

.08    Edge Seaming: A bead of seam adhesive must be applied to all seam edges of tufted outdoor carpet, as well as all exposed edges. Needle punched carpet normally does not          need exposed edges sealed; however, refer to manufacturer's recommendations.

.09    Rolling: Generally, outdoor carpet will require rolling after installation. The size and weight of the roller to be used should be specified by either the carpet or adhesive                      manufacturer.

.10    Finishing: All seams should be brushed, and protruding pile tufts should be trimmed. Excess adhesive must be removed with a suitable solvent recommended by the                      adhesive manufacturer. The final installation must be cleaned and ready for use.

         Note: For indoor installation of outdoor carpet, follow the procedures outlined for direct glue down carpet, except where outdoor conditions may also exist, such as indoor                  swimming pools, health spas, and indoor-outdoor patios. Do not use flammable adhesives of any kind.

14 • COMPLETION OF INSTALLATION WORK

.01    On completion of carpet work, all loose pieces of face yarn shall be trimmed with scissors, and all carpet and cushion scraps and other refuse removed from the area of Work.

.02    Carpet shall be vacuumed with a beater type vacuum as required to remove dirt, and any soiled spots

.03    All exposed adhesive shall be removed using proper cleaner recommended by the carpet and adhesive manufacturer for each type of carpet and adhesive installed.

15 • PROTECTION OF CARPET INSTALLATIONS

.01    Curing of Adhesive: Traffic over adhesive installations should be restricted for a minimum of 24 to 48 hours to allow proper adhesive cure. Premature traffic can cause                      installation (i.e., adhesive bond) failure. Exposure to water from cleaning or other sources should be restricted for a minimum of 30 days.

.02    Protection: Unless otherwise noted in the specification or approved under scope of trade work, the General Contractor shall ensure that carpets are protected against damage          from rolling loads for 48 hours after the installation and that all carpets are protected by covering with non-staining plywood or hardboard where rolling traffic will occur (e.g.              moving of equipment, appliances, etc.).

.03    The General Contractor shall also ensure that carpet is protected from dirt and traffic damage, or if additional work is to be done after the installation (e.g. painting) using                  suitable impervious non-staining covering materials until floor has been inspected and accepted by Owner and Consultant at Substantial Performance and until ready for use.

         Warning: Plastic sheeting should not be placed over any carpet installation because it may present a slip hazard. In addition, it may trap moisture, retarding adhesive cure              and/or promoting mould and mildew growth.

.04    Temperature Maintenance: Temperatures of indoor carpeted areas shall be maintained above and should never fall below 10°C (50°F), regardless of the age of the                          installation.

16 • PROBLEMS AFTER INSTALLATION

.01    A number of problems may occur after carpet installation. These may be generally corrected in accordance with the following. However, any "carpet" installations problems              must be resolved with the carpet installer and in accordance with the recommendations of the carpet and cushion manufacturer.

.02    Bubbles, Looseness, Buckles, Ripples, and Wrinkles:
  • Correction: If incorrect cushion was installed, it must be replaced! However, the Installer can remove the bubbles or looseness, but the work cannot be guaranteed. The problem may surface again.

  • A power stretcher shall used to stretch the carpet within the area in four directions and the area must be completely empty of all furniture. Knee kickers will NOT stretch the carpet. In many cases, because of the carpet backing, it may be necessary to install two sections of one-inch wide tackless strip or architectural tackless strip to stretch the carpet correctly.

  • The Installer should be prepared to reconstruct the seams, if necessary. Carpet seamed to carpet that is not properly power stretched or loose in an adjoining room usually will not maintain the stretch.

  • When the correct re-stretching procedure is followed it should carry a minimum one-year installation warranty if the correct cushion is used. If not, the work cannot be guaranteed and the problem may well reappear.

.03    Delamination:
  • Delamination occurs when the primary backing releases from the secondary backing. Bubbles or looseness appear which cannot be removed by stretching.
  • Correction: The Installer should push the bubble to the wall. If this is possible, the carpet has not delaminated, but requires re-stretching. However, if the bubble suddenly stops and the Installer's hand moves over the bubble, this indicates delamination. If the condition is not severe, the carpet can be removed from the tackless strip and folded back. Latex is to be applied to the delaminated or loose, area. A heat gun may be used to accelerate the drying of the latex. The carpet is reinstalled. This type of repair is for small areas of delamination. If delamination occurs in a large area or several small areas, the carpet could be classified as defective.

.04    Furniture Indentations:
  • Indentations occur when heavy furniture comes in contact with the face pile and the backing is stretched due to the load. This is noticeable when the furniture is periodically moved and the indentation remains. With extremely heavy articles, indentations are an inherent characteristic.

  • Correction: Indentations may be removed by applying steam. In most cases, synthetic fibres can be lifted and restored to an acceptable appearance. If the condition is severe, this action may not work. If the cushion is too soft or too thick, this corrective procedure will have no effect. To eliminate future problems, the cushion will require replacement.

.05    Fatigue:
  • A very soft cushion will create a feeling of "walking in sand" and make one tired. Too many times, the customer is sold on the idea that they need a "cushion into which they can sink." This is a misconception. A firmer cushion will provide the support required for proper carpet performance.

  • Correction: The only solution to this problem is to replace the cushion with a denser product.

.06    Matted or Crushed Carpet Fibres:
  • Carpet fibre may crush or matt if they are under a heavy constant load and/or because the cushion is too soft. The correct cushion will enhance the appearance of the carpet and support the backing, which increases the durability of the product

  • Correction: The only solution to this problem is to replace the cushion with a product that is recommended for the type of installation involved.

.07    Splitting or Open Seams:
  • This problem may be due to the use of too soft a cushion where the vertical movement in the cushion causes the seaming tape to split. This is not an installation-related problem if an incorrect cushion was installed. A "trampoline" effect has been created.

  • Correction: The furniture must be removed from the room and the carpet removed from the tackless strip. The existing seaming tape is to be removed and the seam reconstructed and the carpet then reinstalled. This however, is a temporary repair because the cushion allows too much movement. This situation will occur again. A cushion product that is suitable for the installation should replace the cushion.

  • In many of the above noted cases, even if the carpet is re-stretched, a future re-stretch can be anticipated because of the vertical movement of the carpet if the cushion is not replaced.

.08    Carpet Does Not Match at the Seams:
  • Mismatched seams occur due to the following:
    • The carpet sections are not from the same dye-lot.
    • The sequence of the roll numbers is not followed.
    • The carpet pile does not run the same direction to achieve an acceptable side match.
    • The installer is not qualified to perform the work

  • One way to determine if the pile is running the same direction is to lay a paper on one side of the seam. Rolling a pencil on top of it will move the paper in the direction of the pile. If in repeating this procedure on the other side of the seam the carpet does not move in the direction of the other section, a problem may exist. There are circumstances where this may not work, but in most cases it is a good indicator.

  • Manufacturing variations in tufting, dyeing, printing, or shearing may cause a colour, texture, or pattern mis-match at the seam. These problems are generally noticeable during the installation of the carpet. These issues must be discussed and addressed prior to ordering carpet and at the time of installation if they occur.

  • Many Manufacturers do not guarantee an exact pattern match. This must be clearly understood by all parties concerned prior to ordering the carpet and should be clarified in writing if an exact match is expected.

.09    Carpet is not Trimmed Smoothly Around the Perimeter of the Room or Area:
  • This results from the installation process and if the carpet has not been cut short, it is easily remedied.

  • Correction: The installer must trim the areas properly if not cut short. If the carpet is cut short this may possibly be corrected once all furnishings have been removed by removing stretched-in carpet from the tackless strip and re-stretching and then re-trimming the carpet or by peeling back adhered carpet, stretching and re-adhering it, and then re-trimming the carpet. In either case, this must only be done if and when approved by the carpet manufacturer.

.10    Carpet is "Smiling" on the Stairs:
  • Certain types of carpet are not designed for installation on stairs. This must be discussed at the time of selection. It is too late once the installation commences. Carpet is constructed in rows and when folded around the curvature of the stair, in some designs, the row is very noticeable. It is suggested that if the carpet is to be installed on a staircase, that the carpet be folded to verify satisfaction with this type of appearance. It is not an installation problem.

.11    Staples are Visible Through the Installation:
  • The electric tacker is one of the most misused installation tools. When properly used, it assists in achieving a proper installation. When improperly used to speed up the installation, the carpets fibres are stapled flat and the uniform appearance disappears. There is nothing more unsightly than to look up at an upholstered ledge from a lower floor in a beautiful carpet and see dimples and staples in the installation.

  • When used by an inexperienced installer, this becomes a quick way of attaching carpet to the stairs and ledges and will display a very unsightly appearance. Instead of creating a fine upholstered stair much like an upholstered piece of furniture, an inexperienced installer may decide to staple all sections of the carpet without planning a proper installation. Fine upholstered furniture is costly, so are beautiful upholstered staircases. Each requires the time of an experienced installer.

  • Before the work begins however, the staircase must be constructed in a manner that will allow the Installer to provide a beautiful installation. In some instances some Builders are not allowing ample edges over which to upholster.

.12    Dimples Appearing in the Carpet Around the Perimeter of the Room or Area:
  • This is a sign that the Installer has stapled the carpet to the tackless strip, which is not acceptable. The removal of these staples is time-consuming. This unacceptable method of securing the carpet to the tackless strip is used instead of using a power stretcher. There is also a possibility that tackless strip with incorrect pins was used.

.13    Small Holes Appearing in the Carpet Around the Perimeter of the Room or Area:
  • A tool referred to as a "Spike" attached to the power stretcher pole and hooked onto the tackless strip, "digs" its way into the flooring leaving holes in the carpet, cushion, and substrate. This is not an acceptable installation practice. Inserting tufts may repair the holes.

  • Holes will also appear in areas near the wall or seam that are the result of bent power stretcher (or knee kicker) pins.

.14    Direct Glue Down Carpet has Bubbles and/or is Loose:

  • The number one problem with direct glue installations is the lack of sufficient adhesive on the substrate providing a complete transfer of adhesive from the floor onto the carpet backing. The substrate surface must be entirely covered as well as the backing of the carpet. Many times, an incorrect sized-notched trowel or the wrong shape of trowel is used which does not distribute sufficient adhesive. This will result in bubbles, which will occur throughout the installation.

  • Also, it is critical that no one walk or move items on a new adhesive installation for 24 hours as problems will surface in the future because of this action.

.15    Ravelling Occurring Along Seamed Edges:
  • The Installer is required to seal all seamed edges in ALL installations unless otherwise directed by the carpet manufacturer. By running a bead of latex or sealer along the trimmed edges, the loose fibres are sealed and ravelling will not occur. When the procedure is omitted, delamination or looseness may occur at seams. This is a critical part of the installation process.

  • In areas where the carpet is installed in a direct-glue manner and adjoins ceramic tile, it is necessary for the Installer to apply seal sealer to the edges of the ceramic tile and compress the carpet into the seam sealer. This eliminates ravelling.