ASTM C542-05 (2024) PDF

Full title and description

Standard Specification for Lock‑Strip Gaskets — ASTM C542‑05. This specification sets minimum material, dimensional and performance requirements for the “locking” compression (lock‑strip or “zipper”) type gaskets used in building assemblies where resistance to sunlight, weathering, ozone, permanent deformation and loss of gripping pressure are critical.

Abstract

Specifies required properties, test methods, and acceptance criteria for lock‑strip gaskets. Key test requirements include tensile strength and elongation, tear resistance, durometer hardness, compression set, brittleness temperature, ozone resistance, heat‑ageing effects, flame propagation (where required), and lip pressure/grip performance. The standard emphasizes ozone‑resistant compounds not reliant on removable surface protection.

General information

• Status: Historical / superseded (reapproved 2011; replaced by later revision C542‑05(2017)).
• Publication date: Original designation 2005 (C542‑05); reapproval noted 31 May 2011 (effective 01 June 2011).
• Publisher: ASTM International.
• ICS / categories: 91.100.50 (Binders. Sealing materials) — Committee C24 (Building Seals and Sealants).
• Edition / version: C542‑05 (Reapproved 2011); later issued as C542‑05(2017) (superseding revision).
• Number of pages: 5 pages (typical product specification length).

Scope

This specification applies to the locking compression (“zipper”) type of preformed gaskets used as sealing elements in building envelope and glazing systems. It defines performance and material requirements intended to ensure long‑term weatherability, dimensional stability, and retention of gripping/lip pressure under service conditions; flame propagation testing may be waived where permitted by the specifying authority or local code.

Key topics and requirements

• Material: ozone‑resistant elastomer compounds; black unless otherwise specified.
• Mechanical properties: tensile strength, elongation, tear resistance and hardness (durometer) requirements.
• Durability tests: compression set, brittleness temperature, heat‑ageing (hot air) effects, ozone resistance and loss of gripping pressure under load.
• Flammability: flame propagation test referenced (C1166); requirement may be waived by the architect/engineer if allowed by codes.
• Dimensional tolerances: cross‑sectional and lip geometry tolerances and lip pressure (grip) acceptance testing.

Typical use and users

Specified by architects, façade and glazing engineers, building envelope consultants and procurement/specification writers. Used by gasket and seal manufacturers, fabricators, installers of lock‑strip gaskets, and independent testing laboratories to verify compliance to material and performance criteria for weatherseals and glazing infill seals.

Related standards

Referenced and related ASTM standards include Test Method C1166 (flame propagation for dense and cellular elastomeric gaskets), Test Methods D412, D2240, D573, D624, D746 and others for rubber properties; related installation and terminology standards include ASTM C716, C717 and C963. These referenced standards govern the specific test procedures and terminology used throughout the specification.

Keywords

lock‑strip gasket, locking compression gasket, zipper gasket, elastomeric gasket, weatherseal, ozone resistance, lip pressure, glazing gasket, ASTM C542

FAQ

Q: What is this standard?

A: ASTM C542‑05 is a specification that defines required properties and test criteria for lock‑strip (locking compression or “zipper”) type gaskets used in building envelope and glazing applications.

Q: What does it cover?

A: It covers material composition (ozone‑resistant compounds), mechanical and durability properties (tensile, tear, hardness, compression set, brittleness, ozone and heat aging), dimensional tolerances and certain flame propagation testing where applicable.

Q: Who typically uses it?

A: Architects, façade/glazing engineers, specification writers, gasket manufacturers, installers and testing laboratories use this standard when specifying, producing, testing or accepting lock‑strip gaskets for building use.

Q: Is it current or superseded?

A: The C542‑05 text was reapproved in 2011 and is listed as a historical/superseded version; a later revision (C542‑05(2017)) superseded the 2011 reapproval. Users should confirm and cite the latest ASTM document and edition for current procurement or compliance.

Q: Is it part of a series?

A: It is part of the ASTM C24 committee’s family of standards for building seals and sealants and is commonly cross‑referenced with ASTM test methods and installation/specification guides related to gaskets and sealants.

Q: What are the key keywords?

A: Lock‑strip, zipper gasket, compression gasket, elastomer, ozone resistance, weatherseal, lip pressure, ASTM C542.