How to Seal the Crevices in a Commercial Roof?

Crevices, gaps, and openings in commercial roofs — around penetrations, at transitions, between panels, and along edges — are among the most common sources of leaks. Here's how to seal them effectively.

Common Crevice Locations

The most problematic crevice locations on commercial roofs include: gaps around HVAC pipe penetrations, openings where roof sections transition at different elevations, separations between metal panels from thermal expansion, gaps at parapet wall-to-roof transitions, and openings around drains and other rooftop equipment.

Traditional Sealant Approach

Traditional sealants (caulk, mastic, or rubberized compounds) can address individual crevices. However, they require regular inspection and reapplication as they crack and lose adhesion over time — especially in climates with extreme temperature swings. This approach is reactive rather than preventive.

Spray Foam: Permanent Sealing

Spray polyurethane foam is the most comprehensive crevice-sealing solution available. Because it's fluid-applied and expands to fill any void, foam penetrates and seals every gap, crevice, and opening simultaneously. At the Jabala Military Base project, foam sealed thousands of exposed fastener holes in a single application. On any commercial roof, foam addresses every potential entry point in one pass.

For Targeted Repairs

For roofs that don't require full restoration, targeted application of compatible sealant and reinforced fabric tape at specific crevice locations — properly prepared and primed — can provide effective short-to-medium term leak prevention.