AAMA 508 or 509?
Pressure Equalized or Drained and Back Ventilated Rainscreen Systems
Metal Composite Material (MCM) has been used as an exterior cladding material in North American construction for more than 40 years. While an extremely flat sheet material, MCM must first be fabricated into an assembly that can then be installed on a structure. These different assemblies are commonly known as installation “systems”.
This Technical Bulletin will focus on a particular classification of systems called “rainscreen” where system performance is determined by either AAMA 508-21: Voluntary Test Method and Specification for Pressure Equalized Rain Screen Wall Cladding Systems,
AAMA 509-21: Voluntary Test and Classification for Drained and Back Ventilated Rain Screen Wall Cladding Systems, or both. The goal of this paper is to provide a basic understanding of the intended performance characteristics that make each type of rainscreen system unique.
