Abstract :
Weather penetration through rainscreened building claddings is dependent on the air pressure differences existing across joints in the cladding. Apparatus has been built to model the degree of air pressure equalization that can occur across rainscreened joints and its variation through geometric alteration of the joint opening area and joint cavity volume. The results obtained using this equipment predict that a ratio of joint opening area to cavity volume of over 0.05 m−1 will give a pressure equalization percentage greater than 96% for all pressure variation frequencies. The pressure equalization percentage can fall to 77% for lower ratios of joint opening area to cavity volume at high pressure variation frequencies.
