Substrates - Structural Concrete
The reinforced concrete roof slab surface should be finished to provide an even surface free from ridges and hollows. New in-situ cast concrete should be given adequate time to dry out, prior to installing the waterproofing system.
Good roofing practice requires the roof to be free of significant ponding within 48 hours of rainfall. Where the structural deck does not provide drainage or removal of standing water within 48 hours, the substrate should be corrected to provide positive drainage.
It is recommended that all decks in a warm roof construction be sealed prior to installing the roofing system to prevent air infiltration beneath the single ply roofing membrane. Sealing the deck is accomplished by installing a vapour control layer over the deck and sealing around all penetrations.