Torch-down roofing uses a modified bitumen membrane applied with heat from a torch to create a waterproof seal. Over time, fasteners securing the membrane might back out, meaning they loosen and protrude from the surface. This can happen due to temperature changes causing materials to expand and contract, or from poor initial fastening during installation. Another cause is moisture trapped under the membrane causing the substrate to swell or rot, which weakens the hold of the fasteners. To check for fastener back-out, inspect the roof for raised or bulging spots and gently press around fastener heads to see if they're loose. Listen for any unusual movement or sound. If you’re comfortable climbing safely onto the roof, you can visually scan for visible nails or screws that are no longer flush, but avoid walking on areas with suspected damage to prevent further issues.
If you find or suspect fastener back-out, it’s important to address it quickly to avoid leaks or membrane damage. Simple DIY fixes might include sealing areas around loose fasteners temporarily with roofing cement to reduce water infiltration. However, do not try to retorch or reseal the membrane yourself unless you’re experienced, as improper handling can void manufacturer warranties or create fire hazards. When contacting a contractor, ask, “How will you ensure fasteners are secure without compromising the membrane warranty?” and “What method will you use to identify if the substrate beneath is damaged or moisture-compromised?” A professional roofer can safely remove and replace affected sections, ensure proper fastening, and assess the underlying structure. Addressing fastener back-out early prevents costly repairs and maintains your roof’s longevity.