
Dull surfaces such as new concrete disguise sub-floor surface imperfections. Shiny, reflective surfaces such as new vinyl or rubber flooring do the opposite.
According to National Floor Covering Association (NFCA) specifications, the minimum industry standard for sub-floor flatness (surface waviness) when installing resilient flooring is 3/16" over 10' for slab on grade and 1/8" over 10' for suspended slabs.
These images show an example of what finished flooring can look like when installation proceeds over a sub-floor surface that doesn't meet tolerance, in this case, 1/2" over 4' (using a 10' straight edge).
Construction budgets should include an allowance for effective grinding and patching work (not in the scope of work for the flooring contractor according to industry standards). Specifications should clearly direct responsibility for this work to the owner of the slab and/or construction manager, and conversation around expectations and scheduling for such work should be had well in advance of floor installation start date.
NFCA's third party independent inspection service, the 'Quality Assurance Program' (QAP), draws attention to such issues giving busy construction teams the chance to understand, plan and solve issues fairly and in advance of the all important deadline. The alternative is the same old same old disputes over extras, delays, poor quality, hold backs and dissatisfied clients.
According to National Floor Covering Association (NFCA) specifications, the minimum industry standard for sub-floor flatness (surface waviness) when installing resilient flooring is 3/16" over 10' for slab on grade and 1/8" over 10' for suspended slabs.
These images show an example of what finished flooring can look like when installation proceeds over a sub-floor surface that doesn't meet tolerance, in this case, 1/2" over 4' (using a 10' straight edge).
Construction budgets should include an allowance for effective grinding and patching work (not in the scope of work for the flooring contractor according to industry standards). Specifications should clearly direct responsibility for this work to the owner of the slab and/or construction manager, and conversation around expectations and scheduling for such work should be had well in advance of floor installation start date.
NFCA's third party independent inspection service, the 'Quality Assurance Program' (QAP), draws attention to such issues giving busy construction teams the chance to understand, plan and solve issues fairly and in advance of the all important deadline. The alternative is the same old same old disputes over extras, delays, poor quality, hold backs and dissatisfied clients.