Rainscreen Siding & Z- House Construction Update

Siding has begun on the Z house, rainscreen cement panels encase the lower values and the detached garage. These panels are attached using a rain screen detail, which allows water to dry rather then being trapped in the siding and eventually creating rot. Rainscreens are used throughout the world and are a required system for all Canadian government buildings. Rainscreen cladding is the attachment of an outer skin of rear-ventilated cladding to a new or existing building. The system is a form of double-wall construction that uses an outer layer to keep out the rain and an inner layer to provide thermal insulation, prevent excessive air leakage and carry wind loading. The outer layer breathes like a skin while the inner layer reduces energy losses. The structural frame of the building is kept absolutely dry, as water never reaches it or the thermal insulation. Evaporation and drainage in the cavity removes water that penetrates between panel joints. Water droplets are not driven through the panel joints or openings because the rainscreen principle means that wind pressure acting on the outer face of the panel is equalized in the cavity. Therefore, there is no significant pressure differential to drive the rain through joints. During extreme weather, a minimal amount of water may penetrate the outer cladding. This, however, will run as droplets down the back of the cladding sheets and be dissipated through evaporation and drainage