Maintenance 6 min readFebruary 1, 2026
10 Signs You Need a New Commercial Roof
From ponding water to fastener back-out, here are the ten warning signs that mean your commercial roof has reached the end of its useful life.
Visible signs from the ground
Interior water stains — even minor — mean water has penetrated all layers. Fascia and coping damage, granule accumulation in downspouts, and visible sagging along parapet walls are all serious indicators.
What you’ll see on the roof
- Ponding water 48 hours after rain
- Alligatoring or blistering across the membrane
- Split seams and separated flashings
- Fastener back-out on metal systems
- Loss of granules on modified bitumen
- Visible open holes at penetrations
- Sagging deck between structural supports
The 20-year rule
Most commercial roof systems begin significant degradation between years 15 and 25. If your roof is in that window and you’re seeing any of the signs above, it’s time for a professional inspection.