4.1 This practice provides minimum recommendations for preparing and smoothing panel underlayments, thick poured gypsum concrete underlayments, thick poured lightweight cellular concrete underlayments and concrete subfloors with patching compounds. Actual requirements for materials to be used, mixtures, and other details are generally included as part of the project plans or specification details and may vary from the minimum recommendations set forth in this practice.

1.1 This practice includes recommendations for preparing and smoothing panel underlayments, gypsum concrete and concrete subfloors with patching compounds upon which resilient flooring may be installed.

1.2 This practice does not cover the adequacy of the subfloor assembly to perform its structural requirements, which is governed by local building codes.

1.3 This practice does not supersede in any manner the resilient flooring, underlayment or adhesive manufacturer’s written instructions. Consult the individual resilient flooring, underlayment or adhesive manufacturer for specific recommendations.

1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.