This is the second edition of CSA A123.21, Standard test method for the dynamic wind uplift resistance of membrane-roofing systems. It supersedes the first edition, published in 2004 under the title Standard test method for the dynamic wind uplift resistance of mechanically attached membrane-rooting systems.
This test method determines the wind uplift resistance of membrane-roofing systems when subjected to dynamic wind load cycles.
The test methods are
(a) Method 1: mechanically attached membrane-roofing systems; and
(b) Method 2: adhered membrane-roofing systems.
The roofing system consists of a deck and roofing membrane. It includes components such as vapour barriers or retarders, insulation, cover board, etc. It is subjected to a dynamic load sequence that has been developed based on wind pressure records, simulating the effects of wind on membrane-roof assemblies.
Note: The roof membrane may be designated as the plane of air tightness.
Method 1: Testing in accordance with this test method is limited to mechanically attached, reinforced membrane systems having a fastener row separation not greater than 2896 mm (114 in) and fastener in-line spacing not greater than 610 mm (24 in).
Method 2: Testing in accordance with this test method is limited to roof components adhered as a means of resisting wind uplift, without the use of mechanical fasteners or ballast.
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