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 Flooring recommends the following test methods:
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.”
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.
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 Flooring. As a reminder, these 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 below tables.
Following are Armstrong Flooring’s maximum allowable moisture limits and pH limits:
| Product | Adhesive | % Internal Relative Humidity | MVER Pounds Per 1,000 ft2 Per 24 Hours | pH |
| Vinyl Composition Tile (VCT) | S-515 | 95 | 7 | 5 – 11 |
| Vinyl Composition Tile (VCT) | Flip Spray | 95 | N/A | 5 – 11 |
| Vinyl Composition Tile (VCT) | S-319 | 99 | N/A | 5 – 12 |
| Vinyl Composition Tile (VCT) | S-1000 | 100 | 14 | 5 – 14 |
| Safety Zone Tile | S-515 | 95 | 7 | 5 – 11 |
| Safety Zone Tile | Flip Spray | 95 | N/A | 5 – 11 |
| Safety Zone Tile | S-1000 | 100 | 14 | 5 – 14 |
| Static Dissipative Tile | S-202 | 75 | 3 | 5 – 9 |
| Biome, Coalesce, Duo, Exchange, Terra, Theorem, Unify, Natural Creations with Diamond 10 Technology LVT Parallel USA LVT 12 & 20 | S-995 | 95 on grade or above; 90 below grade | N/A | 8.0-10.0 on or above grade; 9.0 below grade |
| Biome, Coalesce, Duo, Exchange, Terra, Theorem, Unify, Natural Creations with Diamond 10 Technology LVT Parallel USA LVT 12 & 20 | S-319 | 99 | N/A | 5 – 12 |
| Biome, Coalesce, Duo, Exchange, Terra, Theorem, Unify, Natural Creations with Diamond 10 Technology LVT Parallel USA LVT 12 & 20 | S-1000 | 100 | 14 | 5 – 14 |
| Biome, Coalesce, Duo, Exchange, Terra, Theorem, Unify, Natural Creations with Diamond 10 Technology LVT Parallel USA LVT 12 & 20 | S-315 (Disc 3/23) | 95 | N/A | 5 – 11 |
| Alterna | S-295 | 95 on grade or above; 90 below grade | N/A | 8 – 10 |
| Fiberglass-Reinforced Sheet Flooring | S-295 | 95 on grade or above; 90 below grade | N/A | 8 – 10 |
| Fiberglass-Reinforced Sheet Flooring | S-299 | 95 | N/A | 8 – 12 |
| Integrated Stair Tread | S-726 | 90 | N/A | 8 – 10 |
| Product | Adhesive | % Internal Relative Humidity | MVER Pounds Per 1,000 ft2 Per 24 Hours | pH |
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 Flooring. As a reminder, these 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.