Managing On-Site Conditions
Substrate acceptance and environment
On-site conditions are the exam's practical core: you manage what you can measure and document. Concrete moisture testing must follow the specified method. ASTM F2170 uses in-situ relative humidity probes; ASTM F1869 uses calcium chloride; ASTM F710 covers moisture testing and preparation. Test before adhesive or patch is applied, map locations, and follow the flooring manufacturer's limit. Test pH as required. Maintain temperature and relative humidity within adhesive and flooring limits before, during, and after installation; HVAC must be operating. Check flatness and levelness, often by ASTM E1155 FF/FL, and correct defects by grinding, patching, or underlayment per specification. Control dust with containment and negative air; protect occupied spaces and finished work.
Daily documentation
Daily reports should record crews, areas, quantities, temperatures, humidity readings, delays, visitors, instructions, and site damage. Photograph test locations and existing conditions. Obtain signed substrate acceptance before covering concrete. A short daily record is stronger than a long recollection.
Worked example
A 5,000 sf slab is tested by ASTM F2170. The required number is three tests for the first 1,000 sf plus one for each additional 1,000 sf: 3 + 4 = 7 tests. Readings are 78, 81, 84, 86, 83, 82, and 85 percent relative humidity. The product limit is 80%. Three readings exceed the limit, so the slab cannot be averaged into compliance. The high readings govern their zones; mitigation or a different adhesive system is required per manufacturer. If the specification requires the whole slab to meet the limit, mitigate the full 5,000 sf. Document the readings, test method, probe depth, and calibration before proceeding.
Traps that cost marks
- Averaging moisture readings to pass a limit.
- Testing after the floor is covered or adhesive is applied.
- Relying on a plastic-sheet test when the specification names ASTM F2170.
- Ignoring pH and primer requirements.
- Installing without HVAC or outside acclimation limits.
- Failing to document existing slab cracks and damage.