Use this CSI 3 part SimpleSpecs™ master specification to specify composite metal panels; aluminum faces with the thermoplastic core.
Stainless steel, titanium, zinc, and copper panels can also be added to this section with modifications.
The manufacturers listed in this section produce only the composite panel stock. A fabricator is required to form the panels and provide an attachment system.
What is a rainscreen and how does it work?
Composite metal panels are an exterior rain screen system. This type of siding, (wall cladding) has a cavity between the moisture-resistant surface of an air/water barrier applied to the sheathing to create a capillary break and allow drainage and evaporation.
A rainscreen forms a double-wall construction. The outer layer to keep out the rain and an inner layer to provide thermal insulation. This prevents excessive air leakage, and carry wind loading.
The outer layer breathes, like skin, while the inner layer reduces energy losses. The structural frame of the building remains dry, as water never reaches it or the thermal insulation.
Water that penetrates the wall cavity evaporates and drains between panel joints. Equalized pressure in the wall cavity, prevents water droplets from migrating into the wall cavity, which is known as the rainscreen principal.
Therefore, there is no significant pressure differential to drive the rain through joints. A minimal amount of water may penetrate the outer cladding during extreme weather.
What is an equalized rainscreen?
When the ventilation openings are large enough for the air pressure to nearly equalize on both sides of the rain screen, its rainscreen wall systems are often referred to as a pressure-equalized rainscreen wall. However, this has been criticized as being redundant and is only useful to scientists and engineers.
Related SimpleSpecs™ master specifications:
Panels require structural support, typically from steel framing. See section 07 05 46 Rainscreen Attachment System.