Armstrong Flooring Recommended Underlayment Panels for the Installation of Resilient Flooring

General Requirements

Armstrong Flooring resilient flooring can be installed on suspended wood, OSB, or a treated plywood subfloor with a 1/4″ underlayment and a minimum of 18″ of well-ventilated air space below. Armstrong Flooring does not recommend installing resilient flooring on wood subfloors applied directly over concrete or on sleeper-construction subfloors over, on, or below grade concrete. Subfloors must meet local and national building codes. Trade associations, such as the APA – The Engineered Wood Association, offer structural guidelines for meeting various code requirements. Refer to ASTM F 1482 Standard Practice for Installation and Preparation of Panel Type Underlayments to receive Resilient Flooring for additional information.

Underlayments for resilient floors must:

  • be structurally sound
  • be designed for resilient flooring underlayment purposes
  • be a minimum of 1/4″ thick
  • have panels smooth enough so that texture or graining will not show through
  • resist dents and punctures from concentrated loads
  • be free of any substance that may stain vinyl such as edge patching compounds, marking inks, paints, solvents, adhesives, asphalt, dye, etc.
  • be installed in strict accordance with the board manufacturer’s recommendations

Underlayment Panel Types

Subject to the board manufacturer’s recommendations and warranties, the following underlayments may be used with Armstrong resilient flooring products.

  • Plywood rated as suitable underlayment for resilient floor coverings*
  • Poplar or Birch Plywood with a fully sanded face and exterior glue
  • Luan Plywood, Type 1 (Exterior)**
  • Fiber Reinforced Gypsum Underlayment, Fiber Cement Board & Cementitious Backerboard rated as suitable underlayment for resilient floor coverings

Armstrong Flooring does not recommend installation over the following underlayments.

  • Treated plywood (unless covered with a 1/4″ of APA plywood underlayment)
  • Particleboard
  • Hardboard
  • OSB (unless covered with a 1/4″ of APA plywood underlayment)

Underlayment Panel Table

Plywood,
APA Underlayment*,
Poplar or Birch Plywood,
or Lauan**
Oriented Strand Board
(OSB)
Fiber Reinforced Gypsum,
Fiber Cement Board,
and Cementitious Backerboards
Hardboard
and
Particleboard
Resilient Sheet, Tile, and PlankXNot Recommended***XX

*APA Trademarked Plywood or Equivalent Agency Certified Plywood rated as suitable underlayment for resilient floor coverings such as tile or sheet vinyl. It should have an Exterior or Exposure 1 exposure durability classification and a fully sanded face. APA plywood underlayment grades recommended for areas to be covered with resilient non-textile flooring are A-C, B-C, C-C Plugged or C-C Plugged EXT when marked “sanded face.” Also, Marine EXT or sanded plywood grades (A-C, B-C, A-D or B-D) marked “Plugged Crossbands Under Face,” “Plugged Crossbands (or Core),” “Plugged Inner Plies” or “Meets Underlayment Requirements.”

**Lauan Plywood, when used as an underlayment, should be Type 1 (Exterior). There is a wide variety of quality and species classed as lauan. Some may present severe problems such as discoloration, indentation, loss of bond and delamination when used as an underlayment.

***Oriented Strand Board (OSB) is not recommended under Armstrong resilient floors unless it is covered with a 1/4″ APA plywood underlayment. OSB is acceptable under Rigid Core flooring and ToughGuard II Modified loose lay. 

Note: Regardless of the type of underlayment used under Armstrong resilient flooring, the responsibility for warranties and/or performance guarantees for the underlayment rests solely with the underlayment manufacturer and/or supplier and not with Armstrong Flooring.

The types of subfloors and underlayment panels described are intended only as a guide and should not be construed as an Armstrong Flooring warranty for these products.

Disclaimer

Armstrong Flooring cannot be responsible for:
• joint or texture show-through
• tunneling and ridging over underlayment joints
• discoloration from stain sources in the panel, regardless of the type of underlayment panel used
• underlayment panel problems caused by local climate conditions, basement wall and subfloor construction, or improper installation

We strongly suggest that you secure a written guarantee and installation instructions from the supplier or manufacturer of the underlayment board being used.

Updated on August 25, 2022