D03B Selection

D03B - MATERIALS SELECTION

D03B-1 General & Technical Information
D03B-2 Choosing hardwood flooring
D03B-3 Hardwood flooring selection criteria
D03B-4 Final appearance
D03B-5 Other considerations - Acoustical underlayment - Vapor Retarders - Radiant Heat

Preface:
This study guide covers selection requirements for solid and engineered strip, plank, and parquet hardwood flooring and related materials.
This study guide does not cover selection requirements for laminate wood flooring which is included under Part E03B - Laminate Flooring or for bamboo flooring which is included under Part F03C1 - Bamboo Flooring.

1 • GENERAL AND TECHNICAL INFORMATION

.01 Hardwood flooring manufacturers and suppliers have samples as well as technical information on their products available to the design authority. Some caution should be exercised in reviewing this material so that a manufacturer's particular hardwood flooring type can be fairly compared to the same type from another manufacturer. This involves careful scrutiny of the material specifications and test data.

.02 Technical information regarding installation methods is also available from hardwood flooring manufacturers and suppliers in regard to their specific products. General information on product installation is also available to a degree, from Provincial Floor Covering Associations.

2 • CHOOSING HARDWOOD FLOORING

.01 Why do people choose hardwood flooring? There are a number of reasons why they might, some of which may include the following:

Visual appeal and natural beauty.
Cleanliness and health reasons.
Because it is a natural (green and sustainable) material.
For its variety - no two trees, or even pieces from the same tree, are alike.
For its colour and wood's ability to receive many types of stains and finishes.
For its durability.
For its retention of value.

Whatever the reason or reasons for the desire to use hardwood flooring is a fact.

.02 As a natural material, wood has great variation in both grain and colour within any species, and no two pieces of the same species cut from the same timber are the same. In addition, all wood to varying degrees is sensitive to light and oxygen and will change colour as it ages with some developing a patina. As well, different applied finishes will dramatically alter the look of any species of wood, especially imported ones. Because of this variety of appearances and the "warmth" of wood, hardwood has and still is being used as a floor covering in many different locations.

.03 In choosing hardwood as a flooring material, Owners and Consultants (designers and specifiers) have a wide variety of species, patterns, and finishes as well as both solid and engineered hardwood flooring and a variety of installation methods from which to choose from. The selected hardwood flooring must not only be aesthetically pleasing to the owner (the end user) and the designer but must also retain an attractive appearance throughout its life expectancy. Paying careful attention to a number of factors in the initial selection process will ensure that a visually attractive and durable installation will be achieved.

3 • HARDWOOD FLOORING SELECTION CRITERIA

Many factors enter into choosing the "right" type of hardwood flooring and system to meet a project's requirements. After considering general flooring selection criteria noted in Part A17, a number of other things should be considered:

.01 Hardwood Cost and Quality:

The cost of hardwood flooring is based on many factors, including the type of wood species (oak, maple, birch, reclaimed, etc.), grade and cut, type (strip, plank, or parquet), pattern (e.g. herringbone, inlays, insets, etc.), construction method (solid or engineered), installation method (floating, mechanically fastened, glued down, or glue-less), wire brushing, hand-scraping, distressing, and finish (site or pre-finished), natural oil, oil modified polyurethane, swedish (conversion varnish), waterbased finishes.
The size of the project will also effect the dollar price per square foot. For example smaller spaces still require the same set up at the beginning of the installation and pack up at the end of the installation as large projects.
The total cost for hardwood flooring is also affected by the following requirements where appropriate:
- Delivery, storage and handling of flooring materials, to and on site.
- Removal and disposal of existing materials (e.g. flooring and baseboards).
- Acceptability of substrate (including moisture content) and supporting construction (including stiffness / deflection).
- Substrate preparation requirements.
- Special requirements such as installation over radiant heating.
- Underlayment requirements (acoustical / thermal cushion and installation).
- Installation method (floating, mechanically fastened, glue-down including choice of adhesives, or glue-less).
- Provision of matching baseboards and stairs (treads, risers, and stringers).
- Maintenance considerations.
- Moving (i.e., removal and re-installation) of furniture in existing areas.
An Owner's appearance, design, and performance requirements for hardwood flooring must be established and a realistic budget drawn up. This amount may limit the range of choices. It is up to the designer to select an appropriate hardwood flooring system (material, finish, and assembly) based on a fair and equitable evaluation of materials and costs to meet the requirements. In this regard it is very important to be well informed and to compare "apples to apples".
Purchasing hardwood flooring at special, reduced, or give-away prices often results in consumer / user dissatisfaction. Quality hardwood flooring and installation can never be obtained at the lowest price. Consumers / Owners should not attempt to "save" on long-term appearance and performance or on the method of installation when they know they will be looking at the workmanship over the life of the flooring!
The durability and ultimate cost of a wood flooring installation depends on the type and style of flooring, as well as the species, grade, cut, appearance and the finish selected.

.02 Hardwood Durability and Performance:

The hardness of a wood species is its ability to resist indentation, wear, and marring. Hardwood flooring's durability is determined by the species selected, the type of finish applied, and the amount of traffic it will be subject to. For hardness rating of hardwood species refer to Part D03D - Material Guide - Species.
Traffic Wear: In any building (office, institution, or residence) there are different levels and patterns of traffic. Within each area these levels and traffic patterns will vary from high traffic (such as entrance areas, corridors, stairs, etc.) to medium traffic (offices and open spaces), or to low traffic (such as bedrooms in residences) all depending on the room function and location. The traffic concentration in each could differ greatly going from funnel areas, where large numbers of people must frequently pass (such as entry doors, in front of elevators, etc.), to private offices or residential areas having only a few people in and out each day.
In high traffic areas where the flooring is expected to be sanded and refinished a solid hardwood flooring with a durable low maintenance finish should be considered over an engineered hardwood floor with a thin veneer layer that cannot be sanded and refinished repeatedly. Alternatively such engineered products are used in high traffic areas with the understanding of the owner that wear and tear issues are dealt with by replacing individual boards or whole areas as necessary. Such laminated wood flooring products will be more than adequate in low traffic areas.

.03 Hardwood Species:

Because of the demand for "hardwood" flooring, a great variety of both domestic ( North American) and Exotic (Central and South America, Europe, South East Asia, Africa, Australia) hardwood and softwood species are used. Examples:

Ash
Beech
Birch
Cherry
Mahogany
Chestnut
Cypress

Douglas Fir
Elm
Hickory
Jarrah
Jatoba
Maple
Merbau

Oak
Paduk
Pine
Teak
Walnut
Wenge

2. The cost of each species will vary due to availability, method of cutting to provide grain pattern, thickness and lengths required, and the final grade of the material selected.

3. In addition, some species that are similar in grain, colour, and texture may even be substituted and dyed to appear the same as a more expensive variety.

.04 Hardwood Grades and Variations:

The appearance of a hardwood determines its "grade." There are a variety of grading rules that apply to hardwood flooring. All grades are equally strong and serviceable, but each will present a different look. For an explanation of the characteristics of each grade refer to Part D03E - Material Guide - Grades.
The angle at which a board is cut determines how the finished product looks. Wood flooring is either plain sawn, quarter sawn or rift sawn. Each log yields a certain percentage of each cut.

Plain Sawn: This is the most common cut. The board contains more variation than the other two cuts because grain patterns resulting from the growth rings are more obvious.

Quarter Sawn: This 70 to 90 degree cut produces less board feet per log than plain sawing and is therefore more expensive. Quarter sawn wood twists and cups less, expands and contracts less, and wears more evenly.

Rift Sawn: This cut is similar to quarter sawing but the cut is made at a slightly different angle (45 to 70 degrees).

Plain Sawn Oak

Rift and Quarter Sawn Oak combination

Rift Sawn Oak

The selection of a premium grade / cut of hardwood will obviously increase the cost of the flooring installation.

.05 Appearance and Patterns:

Since the use of hardwood flooring in any area can have a major effect on the overall appearance the use of an appropriate pattern of flooring is extremely important. The following should be considered when appropriate:
1. Choice of style (strip, plank, parquet, or herringbone) and direction of installation (e.g. parallel or diagonal).
2. Board size (width and length of strip or plank or size of panels) and arrangement (e.g. same width throughout or alternating widths)
3. Cut / grain appearance and distribution.
4. Finish (colours and stains) that will highlight the grain and pattern.
5. Use of borders and/or inlay patterns to compliment the desired total effect.
The appearance of strip and plank flooring (including patterned flooring pieces) can be altered by modifying the adjoining edges and ends of material (in lieu of square / smooth edges):
1. Square Edge – no Bevel – The edges of all boards meet squarely creating a uniform, smooth surface that blends the floor together from board to board.
2. Micro-Beveled Edge – The micro-bevel is meant to help hide minor irregularities, such as uneven plank heights.
3. Eased Edge: This treatment lightly sands the "panel" edges to remove the sharp corners to provide a rounded or "eased" edge.
4. Heavy or Hand-Bevel – These floors also hide floor irregularities, and have a very distinctive deep groove in them. The beveled edge planks lend themselves to an informal and country decor. The hand-beveled planks have a rustic, hand-hewn look.
5. Refer to Part D03C - Material Guide - Flooring for edge details.

Square Edge (site finished)

Micro Beveled Edge

Eased Edge

Heavy or Hand Bevel

.06 Hardwood Flooring Types / Systems:

In choosing hardwood flooring there are basically three different types or systems to choose from:
1. Solid Flooring: This type of hardwood flooring uses solid wood material in strip or plank form in various widths and lengths and in parquet form which can be site or factory finished.
2. Engineered Flooring: This type of hardwood wood flooring (also referred to as laminated not laminate hardwood flooring) is available in strip or plank form in various widths and lengths and in parquet form and consists of a décor layer (sawn or veneer hardwood), a core layer (plywood, MDF, or HDF), and a backing / balancing layer. This 3 or 5 ply composition is laminated together to produce a dimensionally stable product that is usually factory finished although it can be site finished as well. Because of its construction (and prefinishing) it is usually costs less than solid hardwood flooring.
3. Acrylic Impregnated Flooring: Although considered a finish by some this type of "injected wood" flooring consists of solid hardwood that is impregnated with acrylic under pressure, creating a super-hard, extremely durable "wood" floor that is usually used in commercial and institutional applications. This process results in a wood flooring that is more acrylic than wood and one that is usually more costly than other hardwood floor finishes.

Engineered

Solid oak tongue and groove

Prefinished Solid strip

Mosaic or Parquet Flooring

.07 Style and Size:

In choosing one of the hardwood flooring types there are a number of styles and sizes to choose from:
1. Strip Flooring: This style of flooring as the name implies uses narrow boards or strips of hardwood in various lengths and in widths from 25 to 75 mm (1" to 3"). Using strips create a linear effect in a room often promoting the illusion of a larger space. The direction of strips may depend on the sub-floor joists when the material is nailed down.
2. Plank Flooring: This style of flooring uses wide boards or planks in various lengths and in widths over 75 mm (3”) up to 300 mm (12”). Planks create a linear look similar to strip flooring and may be installed in various widths and in conjunction with strip flooring.
3. Parquet Flooring: This style of flooring consists of small strips or fillets of hardwood that are bonded together in tile form. Tiles are available in many simple to intricate patterns and designs.
4. Patterned Flooring: This style of flooring uses short strips" of hardwood flooring that are installed in various pattern configurations (e.g. herringbone)

.08 Finishes:

The choice of a finish (stain and colour) is a very subjective matter and one of personal choice. As one of the two main decorative elements within a space (the other being walls) the choice of a hardwood stain becomes very important in setting the "tone" and in contributing to the ambiance of the space that it is in. A hardwood stain or colour can be a low gloss light natural one, or it can be a vibrant high gloss dark one becoming the focal point of the area or room, making a statement.
All woods are sensitive to light and/or oxygen, and over time, will change colour, developing a unique patina. Native species, such as cherry, darken over time. Walnut, on the other hand lightens. Hardwood flooring must be finished not only to protect the wood but also to maintain a consistent colour.
Hardwood flooring may be site finished after installation or be pre-finished at the place of manufacture. Each finish has it advantages and disadvantages. In general, water-based finishes tend to inhibit the degree of colour change, while oil-based finishes allow a more pronounced change to occur. For an explanation of finishes refer Part D04D – Finishing Guide.

4 • FINAL APPEARANCE

In order to develop a clear understanding of what a completed hardwood flooring installation will look like and how it will perform there are a number of factors that also must be considered during the initial selection process:

Selection of any hardwood material should be made from actual large-scale samples of the species and not from a small sample chain set or from photographs. In some instances it may be best to view a large number of actual pieces or an actual installation of the selected species material with the selected finish.
Selection of a hardwood species should also be made from the full range of colour and grain samples that will occur within the selected species grade to show the variations that are to be expected. It should also be ascertained if the Consultant / Owner wants some of the colour and grain variations graded out of the material selected to be used.
Finish options should be reviewed (e.g., the types of stains, finishes, and gloss levels available) and once selected should be applied to actual samples of the selected hardwood species to indicate the final overall look.
Sheen levels should be considered carefully. The level of sheen is derived by the amount of light reflection created by the finish. Each manufacturer can use different application procedures that can affect sheen levels. There are different sheen level options (listed below). Products supplied with lower sheen levels such as Satin or Matte can help disguise normal wear and tear hence most manufacturer's apply low reflective sheen levels to their products. The glossier (shinier) the finish, the more natural wear and tear is noticed.
- Gloss - Highly reflective (site applied). Likely to show wear and tear sooner than a finish sheen that reflects light less such as Satin or Matte.
- Semi-Gloss - Less reflection
- Satin - Less reflection
- Matte - Lowest sheen.
It is also important to clearly note what the selected species material will look like when it is initially sanded and site-finished or pre-finished and what it will look like after it has "aged" in place.
Finally, it is also important to review what the finish and gloss level will look like under actual artificial and natural lighting conditions and what it will look like when exposed to direct sunlight and UV rays. The latter should be conducted using a finished sample that is "partly" exposed to sunlight for a few days. The unexposed part will indicate the short-term effects of sun and UV rays on the finish.

Note: In particular, Jatoba (Brazilian Cherry) is known for it's darkening characteristics.
This picture gives an example of how this species of wood darkens when exposed to sun light. Areas that are hidden from light stay the original colour. This process happens over time, on average 3 to 6 months depending on the amount of exposure to sun light.

5 • OTHER CONSIDERATIONS

There are a number of other items that must be considered when choosing hardwood flooring.

Acoustical Issues: Because of the hard surface of hardwood flooring the generation of airborne and impact noise may be a concern within and between adjoining spaces. Where this is an issue the use of an acoustical underlayment / separation layer between the hardwood flooring and substrate surface below to reduce such noise must be considered. Installing hardwood flooring over an "acoustical" underlayment may provide an adequate noise reduction coefficient. In all cases however, the acoustical ratings specified by underlayment manufacturers must be verified. For an explanation of acoustical testing and requirements refer to A08C - Acoustical Issues.
Vapor Retarders: Due to the hygroscopic nature of wood products, vapor retarders / membranes / barriers are required to protect wood flooring products from the negative effects of moisture. Permiability of vapor retarders is an important consideration to avoid expansion and moisture related issues. The following is a guide issued by NWFA and NFCA for choosing a vapor retarder with the recommended permeability and vapor retarder classification for wood flooring:
1. Vapor Permeance: A property that describes the ease with which vapor molecules diffuse through a material. More specifically, vapor flow across a unit area that will flow through a unit thickness under a unit vapor pressure difference.
2. Perm rating: The standard measure of the water vapor permeability of a material. The higher the number, the more readily water vapor can diffuse through the material.
3. Vapor retarder (also known as a vapor diffusion retarder): A layer of material that is used to control the rate at which moisture can move through a material.
  1. Vapor Retarder Classifications: The International Residential Code describes three classes of Vapor Retarders (Class I, Class II, Class III) when tested in accordance with ASTM E-96 Test Procedure A 0 the desiccant or dry cup method):
    1. Class III vapor retarder >1.0 perm. Class III vapor retarders are also considered Vapor Semi- Impermiable Membranes.
    2. Class II Vapor retarder >0.1 perm and ≤1.0 perm. Class II vapor retarders are also considered Vapor Semi- Impermiable Membranes.
    3. A. Class I vapor retarder ≤0.1 perm. Class I vapor retarders are also considered Vapor Impermiable Membranes or Vapor Barriers.
  2. Vapor Retarders over concrete subfloors:
    1. Every concrete slab on-and below- grade should have a Class I vapor retarder installed directly beneath it, prohibiting the passage of ground moisture through the slab. If the vapor retarder below the slab has been compromised or left out, moisture will be able to move freely through the slab and into the flooring system. Unfortunately, there is no way of knowing whether there is an intact vapor retarder in place below the entire slab.
    2. Moisture test the concrete substrate in accordance with the most current ASTM standards, to align the moisture control system and installation method with the condition of the slab. All moisture tests give a result "at the time the test was performed", but do not give a permanent condition of the substrate due to changing conditions such as water tables (ground water) and Relative Humidity.
    3. Install a Class I impermeable vapor retarder when calcium chloride readings are greater than 3 lbs and/or relative humidity readings are greater than 80%.
    4. In on-and below-grade applications, due to the ever- changing moisture variability with a concrete slab, and the likelihood of sub-slab moisture barrier degradation over time, a Class I impermeable vapor retarder is always recommended.
    5. Depending upon your installation method, the type of vapor retarder will vary.
      1. Multi-layer systems include using two layers of fabric membrane such as fibreglass mats, or asphalt-saturated felt or Kraft paper. The first layer is adhered to the slab in skim coat of an appropriate cold-stick asphalt-mastic or hot-mop adhesive, and the second layer is adhered to the first layer using the same fabric and adhesive.
      2. Class I underlayment sheet-good vapor retarders may include 6-mil polyethylene fit or other premium polymer sheet goods, closed-cell foam pads, or peel-and-stick membranes. These sheet good must be laid flat on the subfloor, covering the entire surface, with no holes or penetrations. Follow the manufacturers specific instructions on application, moisture control limitations, and installation methods.
      3. Class I liquid- applied vapor retarders may include rolled-troweled - or sprayed-on sealers, epoxies, or urethanes. Follow the manufacturers specification instructions on mixing, application, surface preparation, compatibility, moisture control limitations, and warranties.
      4. Many vapor retarders are designed to be used in conjunction with compatible adhesives. When gluing down a wood floor, only use vapor retarders and adhesive systems that are compatible.
Radiant Heating: While radiant floor heating will not harm most hardwood flooring, variances in moisture content will cause it to move in numerous ways. When installing solid or engineered hardwood floors, moisture content is a key factor to successful floor performance. Adding heat to the floor assembly makes attention to moisture even more critical. The installation of hardwood flooring over radiant heated substrates is subject to the flooring manufacturer's recommendations. It is important to note that almost all movement in a wood floor is due to moisture and that movement will happen in all wood floors. Therefore, the more constant the moisture content is maintained, the less likely there will be any problems with the floor. Gaps between the boards and checks (cracks in the board) are a result of the moisture content being too low. Warping or cupping is the result of the moisture content being too high or uneven. In either case, it is usually a result of not allowing the wood to adjust to its environment before it is installed.
1. While temperature does not harm the wood, it does affect its moisture content. As the temperature goes up, the moisture content generally goes down. Heating the wood too much will cause it to shrink and gaps will occur between the boards. Once the temperature is lowered, the moisture returns and the gaps close up.
2. In most climates, winter air is dryer than summer air. This can cause seasonal gapping between boards and will occur regardless of whether or not there is a floor heating system installed. If an indoor humidity control is not present, occupants should expect some seasonal gapping on any wood floor with or without radiant heating.
3. If solid hardwood flooring is being contemplated for use over radiant heated floors the following factors must be considered:

Solid wood flooring over in floor hot water heating

Engineered wood flooring over in floor hot water heat

As a general rule most hardwood flooring manufacturers do not recommend nor will they warrant the installation of solid hardwood flooring over radiant heated floors (due to excessive shrinkage) but will recommend and warrant engineered flooring over such heating.

Certain Species are known for their inherent dimensional stability such as American Cherry, American Walnut, Mesquite, Teak and others. Other species such as Maple and Brazilian Cherry are unstable. The manufacturer / supplier of hardwood flooring must be consulted in regard to species suitability.
Lighter coloured woods should be avoided if possible because inevitable (black) gapping and cracks between flooring pieces will contrast strongly against the lighter flooring.
Quarter sawn or rift sawn wood flooring is more dimensionally stable than plain sawn wood flooring.
Narrow boards, 57 mm (2 1/4") or less in width, are the best choice of solid wood flooring over radiant heated floors.

.03 Guarantees and Warranties:

For an explanation of warranties and guarantees refer to Part A06 – Guarantees and Warranties.
Material warranties usually cover manufacturing defects of materials and in the case of engineered hardwood flooring may include structural failure and delamination of the flooring material. Material damage due to improper installation, maintenance, and water damage are not covered. Since hardwood flooring is a natural product, there will be variations in colour, tone, and grain. Such variations are not covered by warranties.
Finish warranties are based on proper care and maintenance of the flooring and are available for a number of extended and pro-rated periods (e.g. up to 25 years). Such warranties usually exclude any indentations, scratches or damage caused by lack of proper maintenance, misuse, negligence, spiked heel shoes, pets, insects, water, moisture, erosion, pebbles, sand, other abrasives or insufficient protection on furniture, wet mopping or failure to follow all of the manufacturer's written maintenance instructions. In addition, use of floor care products and cleaning methods other than those recommended by the manufacturer may damage flooring and may void the warranty.
Warranties may be limited to the original purchaser of the flooring and may not be transferable.
If the need of repair and/or replacement of hardwood flooring under warranty arises a number of issues need to be clarified. These include:
1. Will there be charges for furniture removal, etc.?
2. Will there be costs for removal of existing flooring?
3. Will there be costs for supply and installation of new flooring and related materials?
4. Will there be charges for re-finishing?
5. If the existing hardwood flooring is no longer available, what is provided for under the policy?
6. Is the replacement or any other claim pro-rated?

6. Guarantee and warranty claims will require examination by the hardwood flooring contractor / supplier and/or a representative of the manufacturer, and if deemed necessary, by an independent third party inspection service (e.g. NFCA Quality Assurance Program Inspector). Usually proof of purchase must accompany any claim.

.04 Specifying Hardwood Flooring:

Specifying hardwood flooring informs the manufacturer / supplier in exact terms of what species, grade, type of flooring material, and finish is required. Due diligence and a correct and clearly written specification is a necessity to obtain the required results. This should be done by a design professional who clearly understands the specification writing process and requirements using the correct format and content. How is this done?
Having examined the substrate conditions and the type and volume of traffic to which the area under consideration will be subjected to and having selected the material and finish, the next step is to precisely define these elements. These choices must be made to provide optimum performance and durability as well as the desired aesthetics within the budget available and should be carefully discussed with and examined by the various hardwood flooring manufacturers representatives while discussing the project with the architect and/or designer, the specifier, and the contractor where applicable.
To write a correct hardwood flooring specification also requires knowledge of basic construction and how various elements, such as concrete substrates, will influence the hardwood flooring's final performance. The specifier must also be aware of established Code and industry standards, and where applicable, incorporate these within the specification as well. The specification should also be written in such a manner that it allows for the consideration of products from competing manufacturers that conform to the specification requirements.

.05 Caveat Emptor (Buyer Beware):

To alleviate problems resulting from the improper selection and/or installation of hardwood flooring, it is the Consumer's responsibility to be properly informed. Both the design professional and the hardwood flooring dealer also have an obligation to inform the consumer of the pertinent facts in choosing an appropriate hardwood flooring system.
One way to be assured of receiving quality floor coverings and a professional installation is to deal with reputable and knowledgeable firms who will charge a fair and reasonable price for all materials and installation services. Firms that are proud to provide a quality installation are aware that by doing so they have created one more satisfied customer who will return to purchase again or one who will recommend them to others.

END OF PART D03B