For detailed information regarding adhesives and moisture limits please visit: Floorexpert/Subfloors and Underlayments/Concrete/Adhesive and Moisture Limits.

Moisture Testing

Moisture testing is an essential part of determining the suitability of a concrete slab to receive a resilient floor covering. Moisture testing must be performed on all concrete slabs regardless of their age or grade level including areas where resilient flooring has already been installed. Moisture testing should be conducted with the area or building at service conditions, i.e. fully enclosed, weather-tight and with the permanent HVAC in operation. In general, moisture testing should be conducted on concrete surfaces that exhibit the final prepared stage before the installation of the flooring material and before installation of smoothing or leveling compounds.

Armstrong recommends the following test methods:

a. Percent Relative Humidity (RH) in Concrete Slabs - Preferred Method

Testing for internal relative humidity of concrete slabs must be conducted in strict accordance with the latest edition of ASTM F 2170, "Standard Test Method for Determining Relative Humidity in Concrete Floor Slabs Using in situ Probes."

Maximum acceptable internal relative humidity for flooring installations:

Product	% Internal Relative Humidity
Excelon SDT	75
Vinyl Composition Tile (Commercial) installed with Armstrong S-515 Adhesive	90
Medintone, Medintech, Medley, Royal, Solid*, Timberline, Translations, Perspectives Sheet and Tile, Safeguard, Safeguard Spa, Medintech Tandem, Possibilities Petit Point, Connection Corlon, Commission Plus, Residential Felt-Backed Flooring, Linoleum, Natural Creations, Migrations, Vinyl Composition Tile (Commercial, when installed with Armstrong S-89, S-700 or S-750), Residential Tile, Safety Zone, Residential Vinyl-Backed Flooring, Rubber Tile, Stair Treads and Transition Strips	80

All tests must meet the allowable moisture limits Any area that exceeds the allowable moisture limit must be further dried to an acceptable level or treated with a moisture remediation system before flooring installation. Performance of any third-party moisture remediation rests with the manufacturer of that system, not with Armstrong. As a reminder, in situ probe tests cannot predict long-term moisture conditions of concrete slabs. They are only indicators of moisture conditions at the time the tests are conducted.

b. Moisture Vapor Emission (MVER) Test

MVER tests must be conducted in accordance with the latest edition of ASTM F 1869, "Standard Test Method for Measuring Vapor Emission Rate of Concrete Subfloor Using Anhydrous Calcium Chloride." When performing these tests, it is important to remove any curing agents or residues down to bare concrete. The calcium chloride tests are to be performed only on ordinary concrete floors and are not applicable on lightweight concrete, smoothing or leveling compounds, gypsum underlayments, or other fills.

Maximum acceptable moisture emission levels for flooring installations:

Product	Moisture Limits in lbs/1000 sq ft/24 hours
Residential Vinyl-Backed Flooring, Excelon SDT, Rubber Tile, Stair Treads, Transition Strips, Safety Zone using S-230	3.0
Vinyl Composition Tile (Commercial) installed with Armstrong S-515	7.0
Medintone, Medintech, Medley, Royal, Solid*, Timberline, Translations, Perspectives Sheet and Tile, Safeguard, Safeguard Spa, Medintech Tandem, Possibilities Petit Point, Connection Corlon, Commission Plus, Residential Felt-Backed Flooring, StrataMax, Alterna, Natural Living, Natural Personality, Linoleum, Natural Creations, Migrations, Vinyl Composition Tile (Commercial, when installed with Armstrong S-89, S-700 or S-750), Residential Tile, Safety Zone except when using S-230	5.0

All tests must meet the allowable moisture limits Any area that exceeds the allowable moisture limit must be further dried to an acceptable level or treated with a moisture remediation system before flooring installation. Performance of any third-party moisture remediation system rests with the manufacturer of that system, not with Armstrong. As a reminder, calcium chloride tests cannot predict long-term moisture conditions of concrete slabs. They are only indicators of moisture conditions at the time the tests are conducted.

NOTE: On installations where both the Moisture Vapor Emission Rate and Percent Relative Humidity tests are conducted, results for both tests shall comply with the allowable limits listed in the above tables.