ASTM D8484-25 PDF

Full title and description

Standard Specification for Plastic Lumber Materials and Wood‑Plastic Composite Materials Used as Exterior Wall Coverings — specification D8484‑25 defines requirements and exclusions for the use of plastic lumber and wood‑plastic composite products when employed as exterior wall coverings in an exterior wall assembly.

Abstract

This ASTM specification establishes performance and application limits for plastic lumber and wood‑plastic composite materials used specifically as exterior wall cladding. It identifies material types covered and explicitly excludes PVC siding, polypropylene siding, and traditional wood products; it notes that the standard does not cover other composite applications such as decking, stair treads, handrails, guards, or soffits.

General information

• Status: Active (current ASTM active version D8484‑25).
• Publication date: 01 June 2025 (designated D8484‑25, published 6/1/2025).
• Publisher: ASTM International.
• ICS / categories: ICS 83.140.20 (laminated sheets / related building materials classification).
• Edition / version: D8484‑25 (current active edition; previous version listed as D8484‑23).
• Number of pages: 5 pages.

Scope

This specification applies to plastic lumber and wood‑plastic composite materials when they are used as exterior wall coverings as part of an exterior wall assembly. It explicitly excludes use of PVC siding (see ASTM D3679 / D7793), polypropylene siding (see ASTM D7254), and any form of wood products; it also excludes other applications such as exterior deck boards, stair treads, handrails, guards, and soffits. The standard uses inch‑pound units as the standard and provides SI units for information.

Key topics and requirements

• Definition of covered materials: plastic lumber and wood‑plastic composite materials intended for exterior wall cladding.
• Material exclusions: PVC siding, polypropylene siding, and wood (lumber, plywood, engineered wood, coated/painted wood) are not covered.
• Application limits: applies only to exterior wall coverings as part of an exterior wall assembly (not to other exterior uses like decking or soffits).
• Referenced performance considerations: weathering, fire/flammability characteristics (ignitability, flame spread) and related durability expectations are typical considerations referenced in associated product listings and summaries.
• Administrative details: DOI 10.1520/D8484‑25; developed by ASTM Subcommittee D20.20; Book of Standards volume 08.03.

Typical use and users

Primary users are manufacturers, specifiers, product certifiers, architects, façade consultants, building envelope engineers, and code officials who need to confirm suitability of plastic lumber or wood‑plastic composite products for use as exterior wall coverings. The standard aids in procurement/specification and in clarifying when alternate standards (for example for PVC or polypropylene siding) are the appropriate reference.

Related standards

Standard explicitly references and distinguishes itself from other ASTM siding standards such as D3679 and D7793 (PVC/vinyl siding) and D7254 (polypropylene siding). The document also appears alongside earlier D8484‑23 and is maintained within Committee D20 (plastics). The standard notes there is no known ISO equivalent.

Keywords

plastic lumber, wood‑plastic composite, exterior wall covering, cladding, weathering, flame spread, ignitability, plastic composite, exterior facade, ASTM D8484‑25.

FAQ

Q: What is this standard?

A: ASTM D8484‑25 is a standard specification that sets out requirements and application limits for plastic lumber materials and wood‑plastic composite materials when used specifically as exterior wall coverings.

Q: What does it cover?

A: It covers the intended use, material scope, and exclusions for plastic lumber and wood‑plastic composite cladding on exterior walls; it does not cover PVC or polypropylene siding, ordinary wood products, or uses other than exterior wall coverings (for example decking or handrails).

Q: Who typically uses it?

A: Manufacturers, product developers, architects, façade engineers, specifiers, testing labs, and code/approval authorities who need to verify that a plastic lumber or wood‑plastic composite product is appropriate for use as exterior wall covering.

Q: Is it current or superseded?

A: Current — D8484‑25 is the active edition (designation year 2025). ASTM lists it as the active version (D8484‑25) with the previous edition D8484‑23 recorded; the document was published 01 June 2025 and is active in ASTM’s catalog.

Q: Is it part of a series?

A: It is maintained by ASTM Committee D20 (plastics), Subcommittee D20.20, and is one of several D‑series standards that address plastics and plastic composite materials used in building products; the prior edition is D8484‑23.

Q: What are the key keywords?

A: plastic lumber, wood‑plastic composite, exterior wall covering, cladding, weathering, flame spread, ignitability, ASTM D8484‑25.