Flat Roof Membrane
The waterproof layer covering a flat or low-pitched roof, typically made from felt, EPDM rubber, GRP (fibreglass), or modified bitumen. Membranes can blister, crack, or delaminate with age, causing persistent water ingress that if left untreated leads to structural damage to the roof deck below. Modern EPDM and GRP membranes are expected to last 20–50 years.