Does My Commercial Roof Need 100% Torn-Off?

Not necessarily — and automatically assuming it does can be a very expensive mistake. Here's how to determine whether a full tear-off is truly necessary for your commercial roof.

The 25% Rule

The industry standard threshold for restoration vs. replacement is approximately 25% wet insulation. If moisture has infiltrated less than 25% of your roof's insulation, the damaged sections can be cut out and replaced, and a coating system can restore the remaining roof. Above 25%, a full replacement becomes more cost-effective.

How to Know How Much Is Wet

The only accurate way to assess moisture content is through core samples and — for larger roofs — an infrared scan performed at dusk. These tools identify wet insulation that isn't visible from the surface. Any reputable contractor should perform this assessment before recommending a course of action.

When a Full Tear-Off IS Necessary

A full tear-off is warranted when: wet insulation exceeds 25% of the total roof area, the decking beneath is rotted or structurally compromised, the membrane has delaminated extensively, or building code requires a new roof due to existing layers.

When Restoration Is the Better Choice

When moisture is below the threshold and the membrane is still structurally sound, a coating restoration — at 50–70% less cost than replacement — is almost always the smarter financial decision. Get an honest inspection before agreeing to a full tear-off.