Services · Diagnostics · Moisture mapping
Roof moisture surveys: find every wet square foot — and only replace those.
A roof moisture survey answers the single most expensive question in commercial roofing: how much of this roof is actually wet? The answer routinely changes a full-replacement recommendation into a targeted project at a fraction of the cost.
Schedule My Free Roof Assessment01 · The stakes
Why wet insulation is the real enemy.
The membrane is what you see; the insulation is what you’re paying for. When insulation gets wet, four things happen, all of them expensive:
R-value collapses
Saturated insulation can lose up to 40% of its insulating value, and your HVAC pays the difference every month.
The deck corrodes
Trapped moisture sits directly on steel or wood decking, rusting fasteners and rotting substrate — a structural problem, not just a roofing one.
The damage spreads
Freeze-thaw cycles and vapor drive push moisture laterally, so this year’s 500 wet square feet becomes next year’s 2,000.
Warranties get voided
Manufacturers can deny coverage on failures traced to long-term moisture the owner should reasonably have addressed.
02 · The method
How we map moisture.
We combine methods, because no single instrument tells the whole truth:
The wide net
Infrared thermography
Drone or walk-on, it locates thermal anomalies across the full field.
The cross-check
Impedance & capacitance scanning
Reads moisture non-destructively through the membrane in suspect areas.
The verification
Core sampling
Ground truth: a physical sample of the assembly showing exactly which layers are wet, immediately patched after extraction.
The deliverable is a scaled moisture map with wet areas quantified in square feet, verified by physical evidence, and priced for targeted remediation. Not an opinion — a measurement.
03 · The economics
The economics of replacing only what’s wet.
Suppose a scan of a 60,000 sq ft roof finds 9,000 sq ft of verified wet insulation — 15% of the field. A whole-roof replacement treats 100% of the area. A moisture-guided project replaces the wet 15%, repairs the entry points, and puts the remaining budget where it earns a return.
On most roofs we survey, the wet fraction is a minority of the field. The survey is how you find out whether yours is one of them.
Example · 60,000 SF roof1 tile ≈ 600 SF
9,000 SF replaced · entry points repaired · 51,000 SF of dry roof preserved
Just as important: a dry roof with a failing membrane is often a restoration candidate — a coating system at roughly half the cost of replacement. But coatings require a dry substrate, which is why every legitimate restoration project starts with a moisture survey. Coating over wet insulation seals the problem in and wastes the entire spend.
04 · Timing
When you need a moisture survey.
If any of these sound familiar, the survey pays for itself.
A contractor recommended full replacement and you want the recommendation verified before committing capital
Pre-purchase due diligence on a building acquisition
Before specifying a coating or restoration system
Recurring leaks that repairs never seem to solve — the water is traveling from somewhere else
Establishing the baseline for a new asset management program
05 · Questions
Frequently asked questions.
What owners and facility teams ask before commissioning a survey.
What’s the difference between this and an infrared inspection?
The infrared drone inspection is the survey’s primary instrument, and for many roofs it’s the whole answer. A full moisture survey adds non-destructive impedance/capacitance scanning and core verification, and its deliverable is the quantified moisture map — the document you scope and budget a project from.
Does core sampling damage the roof?
Each core is a small extraction, immediately filled and patched with compatible materials to a watertight condition. The information gained versus the intrusion involved is the best trade in roofing.
Can you survey any roof type?
Nearly all low-slope commercial systems. Where infrared has limitations — ballasted, inverted, or certain closed-cell assemblies — impedance scanning and gridded core sampling do the mapping instead. We match the method to the assembly.
What does a moisture survey cost?
It scales with roof area and access complexity. As a rule of thumb, it costs a small percentage of the project it’s informing — and on any roof where it converts a full replacement into a partial one, it pays for itself many times over.
My roof is only five years old. Could it really be wet?
Yes. Age predicts membrane wear, not moisture. Construction-phase damage, a single unsealed penetration, or a poorly detailed flashing can wet a young roof. Newer roofs are actually the best candidates for early detection, because the damage is still contained.
Before the budget is signed
Measure before you spend.
Before you sign off on a replacement budget, find out how much of your roof is actually wet. The answer usually changes the project.
651-780-7663 · info@lionstarcommercialroofing.com