
Concrete Sub-Floor Preparation: Minor discrepancies in new or existing surfaces can be adjusted by using patching compounds. This is considered, within reason, part of the flooring contractor's work. Where flatness (surface waviness) discrepancies do not meet NFCA or floor manufacturers' tolerances (3/16” over 10’ using the straight edge test method), conditions must be corrected using a Hydraulic Cement Underlayment (HCU), the application of which shall be done by others (general contractor or owner) This may also be undertaken by the flooring contractor as a billable extra. Moisture testing of the parent concrete slab, using the preferred RH In-Situ Probe test method in accordance with ASTM F-2170, must take place prior to application. A surface temperature of more than 10c (50f ), or per manufacturers’ installation guidelines, must also be confirmed before proceeding.
To find NFCA members specializing in the supply of Hydraulic Cement Underlayment click here.
To find NFCA members specializing in the supply of Hydraulic Cement Underlayment click here.