Should You Repair or Replace Your Commercial Roof?
Answer six quick questions for an honest answer, including when you don't need a new roof. It uses the same rules a roofer would, starting with the 25% wet-insulation rule.
Our honest take
This tool gives a general recommendation from your answers, not a diagnosis. Only an inspection and moisture survey can confirm what your roof needs. Nothing you enter is sent anywhere.
How the Tool Decides
The rules come from our repair vs. replacement guide:
- Wet insulation over about 25%, or a soft, spongy deck, points to replacement. Wet insulation loses its R-value permanently, and above that level you're rebuilding the roof anyway.
- Isolated leaks at seams, flashings, or punctures on a roof under 15 to 20 years old usually call for a repair.
- An aging roof with dry insulation is often a candidate for a restoration coating, which can add 10 to 20 years for about half the cost of replacement.
- Recurring leaks, rising repair bills, and a roof past 20 to 30 years push toward replacement.
Want numbers for each option? Use the roof cost calculator, which covers repairs, coatings, and replacement.
Common Questions
Should I repair or replace my commercial flat roof?
It mostly depends on how much of the insulation under the membrane is wet. Under about 25% wet, a repair or a restoration coating is usually the better spend. Over about 25%, or with a soft, spongy deck, replacement is usually required. Roof age, how often leaks come back, and what you spend on repairs each year also matter.
What is the 25% rule for flat roofs?
It's the industry rule of thumb that when more than about 25% of a roof's insulation is wet, replacing the roof is the better spend than repairing it. Wet polyiso insulation permanently loses much of its R-value, and above that level you're effectively rebuilding the roof anyway. An infrared moisture survey with test cuts measures the real percentage.
How do I know how much of my roof insulation is wet?
An infrared survey maps suspect areas from the roof surface, and small test cuts (core samples) confirm whether the insulation is actually saturated. A visual look from the surface can't tell you. We include an infrared moisture survey with our free inspection.
Get the Real Answer for Your Roof
A free inspection with an infrared moisture survey tells you exactly how much insulation is wet, and whether you need a repair, a coating, or a new roof.