ISO 3934:2021

Overview

ISO 3934:2021 - Rubber, vulcanized and thermoplastic - Preformed gaskets used in buildings - Classification, specifications and test methods - provides a standardized system to classify and test preformed rubber gaskets used in building envelopes. The standard covers gaskets for weatherstripping (door/window casings), glazing, infill joints, façade joints and masonry joints. It applies to vulcanized and thermoplastic rubber gaskets and to cellular rubber designed for specified thermal-condition categories.

Key topics and technical requirements

• Classification system: Gaskets are coded with criteria A–G covering type, working compression range, compression force, working temperature (thermal category), compression recovery, stress relaxation and weathering resistance.
• Environmental categories: Thermal (P1–P4), mechanical (X = static, Y = dynamic) and weathering (protected/exposed) conditions are defined to match real-world use.
• Test methods and annexes: Normative test procedures are provided in Annexes A–E:
  • Annex A - Working compression range
  • Annex B - Compression force
  • Annex C - Compression recovery
  • Annex D - Stress relaxation under specified compression
  • Annex E - Variation in length
• Material performance metrics: The standard references established test methods for hardness (Shore A), compression set, tension set, low-temperature brittleness, ageing, stress relaxation and weathering. It also includes requirements for lifetime estimation (Arrhenius procedure) and tolerances on hardness.
• Conformity details: Test pieces should be taken from the actual gasket or equivalent material produced under comparable conditions; results determine the formal classification code.

Practical applications

ISO 3934:2021 is directly applicable to:

• Specifying weatherstripping and glazing gaskets for windows and doors
• Selecting gaskets for façade joints, infills, and masonry connections
• Defining performance criteria for cellular rubber gaskets used in specified temperature ranges

Using the standard helps ensure gaskets meet expected performance for sealing, durability, compression behavior and weather resistance - critical for thermal performance, air/water tightness and long-term building integrity.

Who should use this standard

• Gasket and seal manufacturers (product development, quality control)
• Architects, façade engineers and specifiers writing performance requirements
• Building product test laboratories and certification bodies
• Installers and façade contractors verifying product suitability for climate and movement conditions

Related standards (selected normative references)

ISO 37, ISO 48-4 (Shore hardness), ISO 815 (compression set), ISO 812 (low-temperature brittleness), ISO 3384-1 (stress relaxation), ISO 11346 (estimation of lifetime), ISO 1431-1 (ozone resistance), ISO 4892-2 (weathering).

Keywords: ISO 3934:2021, preformed gaskets, rubber gaskets, vulcanized rubber, thermoplastic rubber, gasket classification, building seals, test methods, compression recovery, stress relaxation, weathering resistance.