Installation Guide
©2019 RI   
REV 11.14.2019 
5 
Readings between the wood subfloor and underlayment should 
be within 3% and have a maximum moisture content of 14%  
or less. 
MOISTURE SUPPRESSANT SYSTEM 
Concrete subfloors that exceed adhesive specifications will require a 
Moisture Suppressant System. Due to complexities associated with moisture 
vapor transmission, emissions and movement of soluble salts (alkalinity) in 
concrete subfloors, we do not offer, recommend, or warranty a specific 
solution for excess moisture in concrete slabs. However, there are many 
companies that offer solutions with warranties for excess moisture in 
concrete slabs.  
RI suggests that you reference the current ASTM F710, “Standard Practice 
for Preparing Concrete Floors to Receive Resilient Flooring”.  
SUBFLOOR PREPARATION 
Careful subfloor preparation is vital for an excellent floor appearance and 
good tile/plank adhesion. The subfloor must be smooth, firm, flat, clean, dry, 
free from defects, and fit for purpose. A suitable smoothing compound 
should be used to ensure that no irregularities show through to the surface 
of the finished floor. In all cases, the subfloor must meet the moisture and 
pH requirements before installation.  
Below and on-grade concrete subfloors must have a suitable vapor retarder 
properly installed directly beneath the slab. Always follow manufacturers’ 
written recommendations for the use and installation of their appropriate 
surface preparation materials  
1.  Record and file site conditions, test results and any corrective action(s) 
taken. It is important to maintain this documentation throughout the 
warranty period.  
2.  Subfloor must be clean (free of dirt, sealers, curing, hardening or 
parting compounds or any substance that may stain or prevent 
adhesion), smooth, flat, sound, fit for purpose, free of movement, 
excessive moisture and high alkalinity.  
3.  Slick surfaces such as power troweled concrete shall be abraded or 
profiled to allow for a mechanical bond between the adhesive  
and subfloor.  










