What determines the longevity of a commercial roof?

1. Material Chemistry & Thickness
   • Thicker single-ply sheets (60 mil vs. 45 mil) withstand weathering longer.
   • High-solid elastomeric coatings block UV and add years to SPF, metal, or aged membranes
2. Installation Quality
   • Proper substrate prep, seam welding, and flashing detailing eliminate 60-70 % of early failures.
   • Independent third-party inspections at punch-list time catch latent defects.
3. Climate & Exposure
   • Sunlight/UV: Accelerates plasticizer loss and membrane chalking
   • Thermal Cycling: In freeze–thaw zones, expansion stresses seams and fasteners.
   • Wind/Hail: Severe wind uplifts edges; 1.75-inch hail can bruise modified bitumen capsheets.
4. Roof Design
   • Positive drainage (< 24 hrs to dry after rain) prevents membrane softening and microbial growth.
   • Adequate insulation limits condensation that corrodes metal decks from below.
5. Preventive Maintenance
   • Regular inspections, cleaning drains, and prompt patching routinely add 25 %–50 % to service life (e.g., turning a 20-year EPDM into a 25- to 30-year performer).