Commercial roof survey
Non-Destructive Roof Moisture Surveys
Our non-destructive roof moisture survey finds water trapped inside the roof assembly and maps its boundaries, without cutting a single hole in your membrane.
Every core cut is a new opening in a roof you are trying to keep dry. Our survey reads the roof instead.
What is a roof moisture survey?
A roof moisture survey is a commercial roof survey that locates water trapped in the insulation and layers beneath the membrane, then maps where it is and how large each wet area has become.
A roof can look dry and sound on top while the insulation under it holds water. Leaks rarely drip straight down. Water travels sideways through the assembly until it finds a seam in the deck, often far from where it entered.
A moisture survey answers three questions a walkthrough cannot:
- Is there water inside the roof, even where no one has reported a leak?
- Exactly where is it, and how many square feet are affected?
- Is the roof still a candidate for repair or restoration, or has too much of it gone wet?
How do you find trapped water without cutting the roof?
We find trapped water without cutting the roof by running our robotic, AI-assisted scan across the surface in a systematic pattern, reading the assembly below for moisture and recording each reading against its exact location.
The traditional approach is the core cut: slicing a sample out of the roof to see whether the insulation is wet. It tells you about one spot, it creates a patch that must be sealed perfectly, and it needs many cuts to say anything about a large roof.
Scan the whole roof
Our scan covers the roof at roughly 50,000 square feet an hour, so every area is read, not a sample.
Locate each reading
Readings are geo-tagged, so every wet area has a position on the roof plan.
Draw the boundaries
Wet areas are outlined and measured, turning a vague problem into a defined repair scope.
Engineer review
A licensed Professional Engineer reviews the findings and stamps the report, delivered within 48 hours.
| Question | Core cuts | Our moisture survey |
|---|---|---|
| How much of the roof is tested? | Only the spots that are cut. | The full roof area that is scanned. |
| Does it open the membrane? | Yes, every cut must be patched. | No, nothing is cut. |
| Does it show the size of wet areas? | Only by making more cuts. | Yes, on a Moisture Map. |
| Can it be repeated each year? | Each repeat adds more patches. | Yes, with no added openings. |
Infrared surveys are another established method that flags suspect areas by surface temperature, usually on a dry evening after a sunny day, and suspect areas are then often confirmed with cuts. Our survey avoids the cut entirely.
What does saturated insulation do to a roof?
Saturated insulation loses most of its insulating value, adds weight to the deck, weakens the bond and fasteners that hold the roof down, and keeps feeding water toward the building long after the rain stops.
- Energy loss: wet insulation conducts heat, so cooling and heating costs climb.
- Weight: water held in the insulation adds load the deck was not designed to carry.
- Attachment: moisture corrodes fasteners and weakens adhesives, reducing wind resistance.
- Spread: wet areas grow outward over time, turning a small repair into a large one.
- Interior damage: water eventually reaches ceilings, inventory and equipment below.
Wet insulation also shortens the roof's remaining life, which is why moisture findings feed directly into our Remaining Service Life estimate.
What does a Moisture Map show you?
A Moisture Map shows the outline of every wet area on a plan of your roof, its size in square feet, and its location relative to drains, curbs and penetrations, so repairs can be scoped and priced precisely.
The map sits alongside the Deficiency Map in our report. Read together, they often show the cause and the consequence: a failed curb flashing, and the wet area spreading from it.
- Contractors can bid the same defined area, so quotes are comparable.
- Repairs can be verified against the map after they are made.
- The following year’s survey shows whether a wet area has grown or been fixed.
Can wet insulation be replaced without a full tear-off?
Yes, wet insulation can usually be replaced without a full tear-off when the Moisture Map shows the wet areas are limited, because only those sections are opened, replaced and sealed while the dry roof stays in place.
That is where the survey pays for itself. Without a map, the safe choice is often to replace the whole roof. With one, the owner can replace the wet sections and keep the rest.
Coatings and restoration systems should never go over wet insulation, because the water stays trapped underneath. A survey before any restoration confirms the roof is dry enough to restore. Our commercial roofing division performs the repair once the scope is set.
More on commercial roof inspections
What else do owners ask about roof moisture scans?
Is a roof moisture scan really non-destructive?
Yes. Nothing is cut, drilled or removed. The membrane is left exactly as we found it.
How is this different from an infrared roof survey?
Infrared reads surface temperature in a limited evening window and flags suspect areas, which are often confirmed with cuts. Our scan reads the assembly directly and maps the result.
How long does a moisture survey take?
About one hour for every 50,000 square feet of roof.
Can you survey a roof that has no leaks?
Yes, and you should. Trapped moisture often exists long before a leak appears inside.
Which roof types can be surveyed?
TPO, EPDM, PVC, spray polyurethane foam, modified bitumen, built-up and coated roofs.
Should we survey before restoring the roof?
Yes. Restoration over wet insulation traps the water. A survey confirms which areas must be replaced first.
Does the survey find the cause of the moisture?
The Deficiency Map records defects such as failed flashings or open seams, which usually explain where the water entered.
When do we get the Moisture Map?
Within 48 hours, as part of the PE-stamped report.
Can wet areas dry out on their own?
Rarely. Water sealed under a membrane has no way out, and it tends to spread.
Is the survey useful for insurance or a sale?
Owners share the report with brokers, underwriters, lenders and buyers as a record of the roof. We cannot guarantee how any party will use it.
Find the water in your roof without cutting into it.
Trusted since 1983 on over 20,000 commercial roofs. California License 435836.