A11 - SUBSTRATE TESTING
A11-1 General
A11-2 Moisture and alkalinity testing requirements
A11-3 Moisture testing
A11-4 Moisture indication testing versus moisture testing
A11-5 Alkalinity testing
A11-6 Testing errors
A11-7 Bonding tests
A11-8 Acceptance of substrate surfaces
A11-2 Moisture and alkalinity testing requirements
A11-3 Moisture testing
A11-4 Moisture indication testing versus moisture testing
A11-5 Alkalinity testing
A11-6 Testing errors
A11-7 Bonding tests
A11-8 Acceptance of substrate surfaces
Preface: This reference guide covers testing of substrate surfaces for moisture and alkalinity as well as testing for adhesive bonding, but not substrate strength testing. Individuals using this guide should verify all facts relative to the particular project requirements.
1 • GENERAL
.01 The presence of excess moisture on or in a substrate that is to receive flooring materials can pose problems particularly if the flooring materials are susceptible to damage in the continuous presence of moisture or if the flooring material is of a type (such as resilient sheet flooring) that will entrap or inhibit the transmission of moisture, causing adhesive bond failure and/or deterioration of the flooring material as well as the substrate (such as wood which will absorb moisture and swell. This encourages mildew, mould, and dry rot).
.02 All new and old concrete surfaces, above, on, or below grade level shall be assessed for both moisture and alkalinity content at a number of locations (three tests for first 100 m² (1000 ft²) and one for each additional 100 m² (1000 ft²) with one within 1000 mm (36") of an outside wall for slabs on grade), and the building must be enclosed with the environmental conditions equivalent to those after building occupancy prior to installing any floor covering material.
.03 Where such tests have been conducted and documented and have shown acceptable conditions at the time of installation, subsequent failure of the floor covering, and/or installation, or failure of the waterproofing or damp proofing membrane under the concrete slab due to the presence of moisture, shall not be the responsibility of the floor covering Contractor.
.04 Repairs to the floor covering material, as a result of moisture or alkali damage from causes noted above, will be the responsibility of the General Contractor and/or Owner.
.05 Moisture Levels in Concrete Substrates
.06 Alkaline Levels in Concrete Substrates
1 • GENERAL
.01 The presence of excess moisture on or in a substrate that is to receive flooring materials can pose problems particularly if the flooring materials are susceptible to damage in the continuous presence of moisture or if the flooring material is of a type (such as resilient sheet flooring) that will entrap or inhibit the transmission of moisture, causing adhesive bond failure and/or deterioration of the flooring material as well as the substrate (such as wood which will absorb moisture and swell. This encourages mildew, mould, and dry rot).
.02 All new and old concrete surfaces, above, on, or below grade level shall be assessed for both moisture and alkalinity content at a number of locations (three tests for first 100 m² (1000 ft²) and one for each additional 100 m² (1000 ft²) with one within 1000 mm (36") of an outside wall for slabs on grade), and the building must be enclosed with the environmental conditions equivalent to those after building occupancy prior to installing any floor covering material.
.03 Where such tests have been conducted and documented and have shown acceptable conditions at the time of installation, subsequent failure of the floor covering, and/or installation, or failure of the waterproofing or damp proofing membrane under the concrete slab due to the presence of moisture, shall not be the responsibility of the floor covering Contractor.
.04 Repairs to the floor covering material, as a result of moisture or alkali damage from causes noted above, will be the responsibility of the General Contractor and/or Owner.
.05 Moisture Levels in Concrete Substrates
- The appearance of concrete can be deceiving and it is never safe to assume that such floors are dry due to the lack of visible moisture.
- Even with adequate curing time, concrete can still present an unacceptable moisture condition by allowing excessive amounts of moisture vapour to pass through to the surface. This can be a problem even on suspended concrete floors.
- Moisture levels in concrete can be affected by a number of factors. The following must be considered when testing concrete:
- Soil conditions of slabs on grade:
- Wet or dry.
- Expansive or non-expansive.
- Free draining or non free draining.
- Water table location (and as affected by seasonal / volume levels and/or tides).
- Inert or contaminated soils and absorptive capacities.
- Sub-base type (cut or fill).
- Base type (included or omitted and if was compacted).
- Screeding type (screed stakes or form screeding).
Type of Concrete:- Water to cement ratio of mix design.
- Type and grade of aggregate.
- Time of transit from plant to site and any delays (for any reason).
- Rotations used in each load.
- Temperature of the concrete mix at time of delivery.
- Slump at time of placement.
- How much water, if any, was added during delivery and placement.
- If water was added to the aggregate (lightweight concrete) and if it was factored into the water to cement calculations.
- Curing method and materials used (impermeable sheet / wet cure, curing / sealing compounds, etc.) and for how long.
- Finishing methods used (hard trowelled, power trowelled, etc.).
- Admixtures used (e.g. calcium chloride, fly ash, plasticizers, water reducers, etc.).
Building Envelope Condition and Environment:- Temperature of room.
- Relative humidity of room.
- Concrete surface temperature.
- Air movement.
.06 Alkaline Levels in Concrete Substrates
- Alkalis are a soluble substance having a pH of more than 7 when dissolved in water, and also are referred to as bases. Alkali occurs in concrete and may be left as a residue on concrete substrate surfaces when the water carrying alkaline salts evaporates during the concrete curing process.
- Note: pH is the symbol used in conjunction with a number to indicate acidity or alkalinity levels. The numbers on the pH scale are 1 to 14 with 7 being neutral. Below 7 is acid while above 7 is alkaline.
- Alkali can leave unsightly salt deposits at the seams of sheet flooring and along the joints of tile flooring. If excessive, alkali may actually corrode or burn the edges of the flooring. It can also build up under flooring causing bumps to occur or it may eat away at flooring adhesives causing adhesive bond failure and damage to the flooring itself. Alkali can also cause dusting of the concrete surface. Flooring adhesives are designed to be alkali resistant up to a pH of 9. Above 9, the alkali becomes excessive and can actually burn skin and start to dissolve concrete aggregate.
- In summary, the presence of alkali can prevent or destroy adhesive bond, carpet backing, and resilient, and hardwood flooring if not eliminated.
- Wood substrates can contain moisture that is present in the subfloor sheathing and support framing (joists, etc.) materials when they are delivered to the site or absorbed during storage (if material is not covered) or in place if the building is not closed in and the flooring and support framing is exposed to the elements (rain, frost, snow, high humidity).
2 • MOISTURE AND ALKALINITY TESTING REQUIREMENTS
.01 Because there is precedence, and in fact, a broad acceptance in the construction industry for independent testing, the NFCA requires that a qualified third party inspection agency be used to test all substrate surfaces for moisture (specifically for vapour emission) and alkalinity levels.
.02 It shall be the responsibility of the General Contractor or Construction Manager to provide and pay for such testing in a timely manner prior to any floor covering installation, so as not to impede the installation of floor covering materials.
.03 Moisture and alkalinity tests shall be conducted using testing methods and devices in accordance with the particular floor covering manufacturer's recommendations and in accordance with NFCA testing and Quality Assurance Program requirements.
.04 The type of tests conducted, the location of each test, and testing results obtained shall be carefully recorded. The time of day and the site conditions in regard to weather, temperature, and humidity shall also be noted.
.05 All such testing shall be conducted with ambient and substrate surface temperatures and humidity levels within ranges specified by the testing standard and material manufacturers recommendations.
.06 The final test results must be in compliance with the manufacturer's recommendations for the adhesive and floor covering materials to be used and acceptable to NFCA Quality Assurance Program requirements.
.07 It is the responsibility of the flooring contractor to verify that moisture and alkalinity tests have been conducted for all areas to receive flooring before installing any flooring materials, and if necessary verify such results with their own moisture indicator testing.
.01 Because there is precedence, and in fact, a broad acceptance in the construction industry for independent testing, the NFCA requires that a qualified third party inspection agency be used to test all substrate surfaces for moisture (specifically for vapour emission) and alkalinity levels.
.02 It shall be the responsibility of the General Contractor or Construction Manager to provide and pay for such testing in a timely manner prior to any floor covering installation, so as not to impede the installation of floor covering materials.
.03 Moisture and alkalinity tests shall be conducted using testing methods and devices in accordance with the particular floor covering manufacturer's recommendations and in accordance with NFCA testing and Quality Assurance Program requirements.
.04 The type of tests conducted, the location of each test, and testing results obtained shall be carefully recorded. The time of day and the site conditions in regard to weather, temperature, and humidity shall also be noted.
.05 All such testing shall be conducted with ambient and substrate surface temperatures and humidity levels within ranges specified by the testing standard and material manufacturers recommendations.
.06 The final test results must be in compliance with the manufacturer's recommendations for the adhesive and floor covering materials to be used and acceptable to NFCA Quality Assurance Program requirements.
.07 It is the responsibility of the flooring contractor to verify that moisture and alkalinity tests have been conducted for all areas to receive flooring before installing any flooring materials, and if necessary verify such results with their own moisture indicator testing.
3 • MOISTURE TESTING
.01 To determine the moisture level of a substrate the following steps must be taken:
.03 When test results indicate that the moisture level of existing (fully cured) concrete substrates exceeds the maximum amount tolerated by the selected flooring product manufacturers, it is recommended that an experienced water proofing / sealing contractor rectify the moisture problems at the Owner's expense, before any type of flooring is installed.
Special note: It is important to recognize that moisture tests of any substrate indicate the amount of moisture at the time of the test only and they should not be used to ascertain the long-term moisture emission rating of any substrate surface.
.01 To determine the moisture level of a substrate the following steps must be taken:
- Visually inspect substrate surfaces for dampness, standing water, or water ingress or leakage from any source.
- Determine which type of test and testing equipment is recommended by the floor covering manufacturer for testing moisture emissions of the various substrate types, except that such measures shall be no less than those required by NFCA.
- Determine the actual amount of moisture contained, or emitted from the substrates using the recommended testing method as a minimum.
- In the case of concrete substrates, determine when the concrete was installed.
- In the case of concrete substrates on or below grade, determine whether or not an effective moisture vapour barrier has been installed.
- In the case of wood substrates, determine the moisture content of the substrate materials (joists, sheathing, etc.) delivered to the site, if they were protected during site storage or subjected to moisture after installation (e.g. rain), when the substrates were protected from the elements (building enclosed), and how long and at what temperatures they have been left to dry.
- In the case of wood substrates on floor framing systems over a crawl space, determine if the space below is in accordance with requirements noted in Part A10 - Acceptable Conditions.
.03 When test results indicate that the moisture level of existing (fully cured) concrete substrates exceeds the maximum amount tolerated by the selected flooring product manufacturers, it is recommended that an experienced water proofing / sealing contractor rectify the moisture problems at the Owner's expense, before any type of flooring is installed.
Special note: It is important to recognize that moisture tests of any substrate indicate the amount of moisture at the time of the test only and they should not be used to ascertain the long-term moisture emission rating of any substrate surface.
4 • MOISTURE INDICATION TESTING VERSUS MOISTURE TESTING
.01 Electronic moisture meters measure the moisture content in a concrete slab, most commonly in terms of percentages. Most electronic moisture meters take readings from the surface, while some probe into the slab. The moisture content of a slab indicates the degree of saturation, but not the vapour emission rate that is occurring. The NFCA requires tests that indicate the quantity of moisture passing through a concrete slab, and for this reason does not accept tests that simply indicate the presence of moisture (i.e. moisture indicator tests).
.02 Moisture Indicator Testing:
.03 Moisture Detection Testing: The following testing measures are acceptable to NFCA in regard to measuring the vapour emission rate that is occurring.
.01 Electronic moisture meters measure the moisture content in a concrete slab, most commonly in terms of percentages. Most electronic moisture meters take readings from the surface, while some probe into the slab. The moisture content of a slab indicates the degree of saturation, but not the vapour emission rate that is occurring. The NFCA requires tests that indicate the quantity of moisture passing through a concrete slab, and for this reason does not accept tests that simply indicate the presence of moisture (i.e. moisture indicator tests).
.02 Moisture Indicator Testing:
- Electronic Moisture Detection Meters: There are a number of electronic pin and pin-less type moisture detection meters available to read surface and internal moisture levels in both concrete and wood substrates. Utilizing such meters must be in strict compliance with the manufacturers recommendations in order to obtain moisture levels present (at the time of testing). The meters must be precisely calibrated to suit the substrate to be tested. The type and length of pin or electrodes used shall also suit the type of substrate to be tested. Some of these metering devices may be limited as to the depth or degree of penetration into the substrate to obtain moisture readings.
- Electronic moisture meters measure content of moisture in a concrete slab, most commonly in terms of percentages. Most electronic moisture meters take readings from the surface, while some probe into the slab. The moisture content of a slab indicates the degree of saturation, but not the vapour emission rate that is occurring. NFCA recommends tests that indicate the quantity of moisture passing through a concrete slab, and for this reason does not recommend using electronic moisture meters.
.03 Moisture Detection Testing: The following testing measures are acceptable to NFCA in regard to measuring the vapour emission rate that is occurring.
- ASTM D4263, Standard Test Method for Indicating Moisture in Concrete by the Plastic Sheet Method: This simple mat test method for concrete substrates involves taping a dense mat / plastic sheet to the concrete substrate surface to detect the presence of capillary moisture. The test shall be conducted in accordance with the requirements of this standard to obtain qualitative moisture results by visual observation after removing the mat covering. The placement time required should be no less than 60 hours.
- ASTM E96, Standard Test Methods for Water Vapour Transmission of Materials: These test methods cover the determination of water vapour transmission (WVT) of materials through which the passage of water vapour may be of importance, such as polyethylene, other sheet materials, fibreboards and other wood products, and plastics. Two basic methods, the Desiccant Method and the Water Method, are provided for the measurement of permeance, and two variations include service conditions with one side wetted and service conditions with low humidity on one side and high humidity on the other. Agreement should not be expected between results obtained by different methods. A method should be selected which more nearly approaches the conditions of use.
- ASTM E1907, Standard Practices for determining Moisture-Related Acceptability of Concrete Floors to Receive Moisture-Sensitive Finishes. These practices include both quantitative and qualitative procedures used to determine the amount of water or water vapour present in or emitting from concrete slabs and criteria for evaluating the moisture-related acceptability of concrete slabs to receive moisture-sensitive manufactured finish products, including certain types of resilient flooring, carpet, carpet tiles, and wood flooring, as well as related adhesives.
- Although coatings, films, and paints are not specifically intended to be included in the category of "moisture sensitive finishes" the procedures included in these practices may be useful for evaluating the moisture-related acceptability of concrete slabs for such finishes.
These practices do not cover the adequacy of a concrete substrate to perform its structural requirements, do not include procedures to determine the presence of non-moisture related impediments to the application of finishes, and do not supersede the specific instructions or recommendations of manufacturers for their flooring finishes.- Hygrometer Moisture Test: This test method for concrete and wood substrates uses a hygrometer testing device to ascertain the percentage of humidity being omitted from a substrate surface. Readings of less than 85% R.H. (Relative Humidity) are considered acceptable. Hygrometers may also read the relative humidity, dew point and temperature of the work place environment.
- Core / Slab Moisture Determination Test: This destructive test method for concrete substrates is generally conducted by certified lab technicians, and involves removing a piece of the concrete slab that is then weighed, oven dried and then re-weighed. Results of 3% (weight difference) or less are considered acceptable.
- ASTM F1869, Standard Test Method for Measuring Moisture Vapour Emission Rate of Concrete Subfloor Using Anhydrous Calcium Chloride: This desiccant test method for testing concrete has come into question in recent years, yet is still recommended by some manufacturers to determine the MVER (Moisture Vapour Emission Rate) from below-grade, on-grade, and above-grade (suspended) concrete floors. Particularly useful when the sub-floor to be tested has an in-floor heating system, making a drill type test such as ASTM F-2170 impracticle or too risky. The test involves placing anhydrous calcium chloride crystals on a concrete substrate and sealing them under a moisture impervious cover for a specific time period to determine the amount of moisture absorbed into the crystals. The crystals must be precisely weighed before and after the test and the difference in weight determined. Moisture test kits are available for this purpose from most flooring supply and installation distributors. The test must be carefully conducted in strict accordance with the test kit manufacturer's detailed instructions. Inaccurate results can occur for a variety of reasons which has led many manufacturers to require both the Calcium Chloride and In-situ probe test to be taken to ensure acceptable moisture levels. Because the test for emission rate requires a minimum of 60 hours to conduct, enough time must be allotted to conduct the test before the installation of any flooring materials.
- This test was initially developed by the Rubber manufacturer's Association (RMA) and has been referred to as the RMA Test. It is has also been referred to as the Moisture Dome Test.
- ASTM F2170, Standard Test Method for Determining Relative humidity in Concrete Floor Slabs Using in situ Probes: This drilled probe test method is highly recommended by NFCA as one of the most definitive tests to determine the percent of relative humidity in concrete slabs. The test consists of drilling a hole into the concrete, inserting a sleeve and humidity probe to measure the humidity over a period of time.
- Moisture emission rates are expressed in either kg/100 m² or lbs/1000 ft² over a 24 hour period.
- As a general guideline, an emission rate of 1.4 kg/100m² (3 lbs/1000 ft²) or less is considered acceptable for most floor coverings. However, and unless otherwise permitted by a flooring product manufacturer, the following maximum moisture emission levels over a 24 hour period are permissible for the following floor coverings types:
- Homogenous Resilient Sheet and Tile Flooring: 1.4 kg/m² (3.0 lbs/1000 ft²).
- Non-Impervious Backed Resilient Flooring: 2.3 kg/m² (5.0 lbs/1000 ft²).
- Porous Backed Carpet: 2.3 kg/m² (5.0 lbs/1000 ft²).
- Impervious Backed Carpet: 1.4 kg/m² (3.0 lbs/1000 ft²).
- Hardwood Flooring: 2.1 kg/m² (4.5 lbs/1000 ft²).
- Laminate Flooring: 1.4 kg/m² (3.0 lbs/1000 ft²).
- Carpet with porous backings can usually be installed successfully where the emission rate is between 1.4 to 2.3 kg (3 to 5 lbs), however the risk of moisture related problems increases.
- All moisture emission ratings must be verified before the installation of any flooring materials.
5 • ALKALINITY TESTING
.01 Alkali Detection Testing (Litmus Paper Test): This simple test method for concrete substrates involves placing distilled (mineral free) water on the concrete substrate surface and then placing a strip of litmus paper into the distilled water. The change in colour of the litmus paper indicates the pH rating of the distilled water that has reacted to any substances present on the concrete substrate. A colour bar scale normally supplied with the litmus paper will allow the tester to determine the pH level of the affected water by matching the affected litmus paper to the scale.
.02 Most calcium chloride test kits now contain alkali testing material. To determine the alkalinity level of the concrete substrate the following steps must be taken:
.04 The pH rating of new concrete will be between 12 and 13. This should lower with drying. In the presence of a continuous water source however, alkali may continue to be drawn to the surface of concrete. A pH range between 7 to 9 may be deemed acceptable for some floor covering materials. A reading above 9 will generally require corrective measures.
.05 When test results indicate that the alkalinity level of new or existing concrete substrates exceed that specified by a floor covering material manufacturer, corrective measures shall be undertaken to ensure that the alkalinity level is brought to an acceptable level. Re-testing shall be performed before the installation of any floor covering material is attempted. If testing continues to show a high alkalinity rating the cause must be determined.
.06 Rinsing with clear water (or soda water) is a good way to lower alkalinity, but it cannot prevent the future deposit of alkali on concrete surfaces. While an acid wash may have been traditionally used to neutralize alkalinity, it is important to remember that acids can leave a residue that can be as detrimental to the installation of any flooring material as the alkali itself.
.07 It is important to recognize that alkalinity tests of concrete substrates indicate the amount of alkalinity at the time of the test only and they should not be used to ascertain the long-term alkalinity rating of any substrate surface.
Special note: Whatever test method or metering device is used for moisture and alkalinity testing, the flooring manufacturer shall be consulted in regard to the acceptance of the specific test readings / results and the flooring supplier informed before any flooring is ordered.
.01 Alkali Detection Testing (Litmus Paper Test): This simple test method for concrete substrates involves placing distilled (mineral free) water on the concrete substrate surface and then placing a strip of litmus paper into the distilled water. The change in colour of the litmus paper indicates the pH rating of the distilled water that has reacted to any substances present on the concrete substrate. A colour bar scale normally supplied with the litmus paper will allow the tester to determine the pH level of the affected water by matching the affected litmus paper to the scale.
.02 Most calcium chloride test kits now contain alkali testing material. To determine the alkalinity level of the concrete substrate the following steps must be taken:
- Check with the adhesive and flooring covering manufacturer for recommended testing and corrective procedures and for acceptable results.
- Place strips of litmus paper on the slab surface and submerge them in distilled (mineral free) water. Note that this test is highly recommended when using water-based adhesives.
.04 The pH rating of new concrete will be between 12 and 13. This should lower with drying. In the presence of a continuous water source however, alkali may continue to be drawn to the surface of concrete. A pH range between 7 to 9 may be deemed acceptable for some floor covering materials. A reading above 9 will generally require corrective measures.
.05 When test results indicate that the alkalinity level of new or existing concrete substrates exceed that specified by a floor covering material manufacturer, corrective measures shall be undertaken to ensure that the alkalinity level is brought to an acceptable level. Re-testing shall be performed before the installation of any floor covering material is attempted. If testing continues to show a high alkalinity rating the cause must be determined.
.06 Rinsing with clear water (or soda water) is a good way to lower alkalinity, but it cannot prevent the future deposit of alkali on concrete surfaces. While an acid wash may have been traditionally used to neutralize alkalinity, it is important to remember that acids can leave a residue that can be as detrimental to the installation of any flooring material as the alkali itself.
.07 It is important to recognize that alkalinity tests of concrete substrates indicate the amount of alkalinity at the time of the test only and they should not be used to ascertain the long-term alkalinity rating of any substrate surface.
Special note: Whatever test method or metering device is used for moisture and alkalinity testing, the flooring manufacturer shall be consulted in regard to the acceptance of the specific test readings / results and the flooring supplier informed before any flooring is ordered.
6 • TESTING ERRORS
.01 All tests must be conducted in strict compliance with recognized testing procedures using personnel thoroughly competent in conducting such testing.
.02 To ensure accurate readings, all testing equipment shall be checked and calibrated before use in accordance with manufacturers requirements.
.03 Individuals conducting the tests must be aware of all circumstances at the Work site that could potentially influence the test results.
.04 Individuals interpreting the test results shall have sufficient experience to validate the test results.
.05 Misinterpretations of test results may occur if:
.01 All tests must be conducted in strict compliance with recognized testing procedures using personnel thoroughly competent in conducting such testing.
.02 To ensure accurate readings, all testing equipment shall be checked and calibrated before use in accordance with manufacturers requirements.
.03 Individuals conducting the tests must be aware of all circumstances at the Work site that could potentially influence the test results.
.04 Individuals interpreting the test results shall have sufficient experience to validate the test results.
.05 Misinterpretations of test results may occur if:
- substrate surfaces are sealed or coated (e.g., concrete sealers).
- metal reinforcement is too close to the surface.
- the humidity or temperature is excessively high or low, etc.
7 • BONDING TESTS
.01 Bond tests are conducted to determine if the flooring adhesive will bond to the substrate. This is to ensure that such surfaces are free from any surface treatment (sealer and curing agents, parting compounds, etc.) or condition (old adhesive, dust inhibitors, oil, grease, paint, varnish or any other finish that is detrimental to adhesive bond.
.02 Such tests are performed by using minimum 450 mm (18") square pieces of the specified flooring randomly spaced throughout the area to be covered and by adhering them to the substrate using specified adhesives recommended by the manufacturer all in accordance with the adhesive and flooring manufacturer's installation instructions. The edges of the samples should be taped to prevent edge drying of the adhesive.
.03 The adhered test samples must be rolled thoroughly and be allowed to set for a minimum of 72 hours before testing for bond strength.
.04 The test samples are then either cut into 25 mm (1") strips or left intact and then pried loose from the substrate surface. If they are securely bonded it can be concluded that the surface is sufficiently clean and acceptable for further application of flooring materials. If an unusual amount of force is required, it can be concluded that the material is "securely bonded" to the substrate.
.05 If sample material is easily peeled off, then the substrate surface is unsatisfactory for adhesive bonding and remedial action must be undertaken to address the surface condition and remove whatever material or condition is inhibiting bonding.
.01 Bond tests are conducted to determine if the flooring adhesive will bond to the substrate. This is to ensure that such surfaces are free from any surface treatment (sealer and curing agents, parting compounds, etc.) or condition (old adhesive, dust inhibitors, oil, grease, paint, varnish or any other finish that is detrimental to adhesive bond.
.02 Such tests are performed by using minimum 450 mm (18") square pieces of the specified flooring randomly spaced throughout the area to be covered and by adhering them to the substrate using specified adhesives recommended by the manufacturer all in accordance with the adhesive and flooring manufacturer's installation instructions. The edges of the samples should be taped to prevent edge drying of the adhesive.
.03 The adhered test samples must be rolled thoroughly and be allowed to set for a minimum of 72 hours before testing for bond strength.
.04 The test samples are then either cut into 25 mm (1") strips or left intact and then pried loose from the substrate surface. If they are securely bonded it can be concluded that the surface is sufficiently clean and acceptable for further application of flooring materials. If an unusual amount of force is required, it can be concluded that the material is "securely bonded" to the substrate.
.05 If sample material is easily peeled off, then the substrate surface is unsatisfactory for adhesive bonding and remedial action must be undertaken to address the surface condition and remove whatever material or condition is inhibiting bonding.
8 • ACCEPTANCE OF SUBSTRATE SURFACES
.01 The maximum moisture and alkalinity levels allowed for any floor covering material (including adhesive, resilient flooring, cushion and carpet) shall not exceed those specified by the material manufacturer.
.02 Since some floor covering products are less tolerant of moisture and alkali than others, the individual floor covering product manufacturer must be consulted to determine the acceptable moisture and alkali ratings for their specific products. If such levels exceed those specified by the manufacturer of any material being installed, the installation must not be attempted.
.01 The maximum moisture and alkalinity levels allowed for any floor covering material (including adhesive, resilient flooring, cushion and carpet) shall not exceed those specified by the material manufacturer.
.02 Since some floor covering products are less tolerant of moisture and alkali than others, the individual floor covering product manufacturer must be consulted to determine the acceptable moisture and alkali ratings for their specific products. If such levels exceed those specified by the manufacturer of any material being installed, the installation must not be attempted.