Installation Guide

REV 11.14.2019

WOOD

• Wood subfloors require an underlayment (double layer construction)

with a minimum total thickness of 1” (25 mm). Use minimum 1⁄4” (6

mm) thick APA rated “underlayment grade” plywood with a fully

sanded face or other underlayment panel that is appropriate for the

intended usage. Install and prepare panels and seams according to

the manufacturers’ instructions. Also, refer to ASTM F 1482 Standard

Practice for Installation and Preparation of Panel Underlayment to

receive Resilient Flooring.

• Many times, wood panel subfloors are damaged during the

construction process or are not underlayment grade. These panels

must be covered with an appropriate underlayment. Underlayment

panels are intended to be used to provide a smooth surface on which

to adhere the finished floor covering. It should be understood that

underlayment panels cannot correct structural deficiencies.

IMPORTANT: Particleboard, chipboard, OSB, flake-board and wafer

board are NOT recommended as underlayment. All these products

have inadequate uniformity, poor dimensional stability, and variable

surface porosity. RI will not accept responsibility for adhered

installation over these subfloors. In all cases, the underlayment

manufacturer or underlayment installer is responsible for all

underlayment warranties.

• Panels intended to be used as underlayment should be specifically

designed for this purpose. These panels should have a minimum

thickness of 1⁄4” (6 mm) any panels selected as an underlayment

must meet the following criteria:

o Be dimensionally stable

o Have a smooth, fully sanded face so grain texture will not

telegraph through

o Be resistant to both static and impact indentation

o Be free of any surface components that may cause staining such

as plastic fillers, marking inks sealers, etc.

o Be of uniform density, porosity and thickness

o Have a written warranty for suitability and performance from the

panel manufacturer or have a history of proven performance

o Any unevenness at the joints between panels must be sanded to

a level surface. Gaps between panels, hammer indentations, and

all other surface irregularities must be filled and sanded.