Will the glue hold?
A bitumen roofing membrane is a vapour barrier. It takes some time (± 3 weeks) for the glue to dry and reach its full adhesive strength. But don’t worry; the initial adhesive strength is sufficient to ensure that your roofing membranes don’t fly off. When applying a top layer over old roofing membranes, you must use a roofing primer to fix the dust. Otherwise, the adhesive strength of the glue will not be sufficient.