Roof Moisture Survey in Orlando, FL

The deliverable from a moisture survey is a written report with a moisture map keyed to the roof zone diagram, the percentage of the total roof area estimated to contain saturated insulation, the confidence level on that estimate, the location and results of all core pulls, and a recommendation on whether the roof is a viable recover candidate or whether the saturation level makes replacement the sound capital decision.

A nuclear moisture gauge (also called a nuclear densometer) detects moisture in roof insulation by measuring the attenuation of low-level nuclear radiation as it passes through the insulation layer. Wet insulation attenuates the signal differently than dry insulation — the instrument detects the hydrogen atoms in water molecules and produces a reading that correlates to moisture content. The gauge is walked across the roof in a grid pattern, with readings taken at intervals of 5-10 feet depending on the suspected moisture distribution. The result is a point-by-point moisture map that can be overlaid on the zone diagram.

Nuclear gauge surveys are the most efficient method for large-area moisture mapping on flat commercial roofs. A 100,000 sq ft roof can be surveyed in a single day. The method works under any weather conditions and does not require a sunny afternoon like infrared does. The limitation is that the readings require calibration to the specific insulation type and density — we pull verification cores to calibrate the instrument and confirm the reading interpretation for each building.

Core samples are the ground-truth confirmation for any moisture survey method. A core pull extracts a cylindrical section of the roof assembly — typically 4 to 6 inches in diameter — through the membrane and insulation down to the deck. The physical sample shows exactly what is in the roof assembly, whether the insulation is wet, whether the deck is corroded, and what previous repairs or alterations have been made in that location.

We pull cores in locations that are targeted based on the moisture map data — at the highest-reading gauge locations, at known leak points, at drain zones where ponding is most common, and at perimeter zones where FBC wind-uplift attachment can be verified. The core pull also gives us a section through the insulation to verify the insulation type and thickness — useful on older buildings where the original specifications are unknown.

Core holes are patched the same day with a compatible material that does not disturb the remaining membrane system. We document the core location on the zone diagram and photograph the core sample at pull and after sectioning. The physical sample can be retained if the building owner wants it for reference or for a second opinion.

Infrared thermography detects moisture in roof insulation by imaging the differential cooling of wet versus dry insulation after a sunny day. Wet insulation retains heat longer into the evening than dry insulation — during the post-sunset cooling period, wet areas appear warmer on an infrared camera. In Central Florida's high-solar-loading environment, sunny days produce a strong differential, which makes the infrared method particularly effective when conditions are right.

The limitation of infrared in Central Florida is the weather pattern. The June-October rainy season means the optimal infrared survey window — a full sunny day followed by a clear, still evening — is often unavailable during the months when moisture mapping decisions are most commonly being made. We run infrared surveys in the November-May dry season when conditions are reliably good, and we use nuclear gauge and core methods during the rainy season when infrared is unreliable.

Infrared results are always confirmed with core pulls — infrared shows the thermal signature of differential cooling, but that signature can also be produced by other conditions (recent rain event on dry insulation, HVAC exhaust patterns, reflective rooftop equipment). We do not issue a moisture finding on infrared alone without core confirmation at the warm spots.

The general industry guideline, and the threshold most manufacturers use for warranty eligibility on a recover, is 25%. If more than 25% of the roof area has saturated insulation, recover is generally not a warranted option and replacement is the recommended path. Below 25%, recover is typically viable if the deck is sound and the membrane is otherwise in acceptable condition. We confirm the threshold with the specific manufacturer before recommending a recover scope.

A nuclear gauge survey on a 50,000 sq ft building takes roughly 4-6 hours of field time, plus core pulls. We deliver the report within 10 business days of the field survey. For buildings where the capital decision is time-sensitive, we can expedite.

Yes. A documented moisture survey with a zone-keyed moisture map and core sample results is the kind of evidence that supports insurance claims for buildings where moisture infiltration caused insulation damage. Florida commercial property claims often involve disputes about pre-existing conditions versus event-related damage — a moisture survey establishes a baseline that can support the claim that the damage was event-related.

That finding means replacement, and it changes the capital decision from a cost comparison to a timing question. We will tell you directly if that is what the data shows — and we will also tell you what the replacement scope looks like, what it costs, and how to time it relative to hurricane season. A fully saturated roof in Central Florida is not a failing grade on your management — it is a common condition on buildings that were not being actively maintained. We see it regularly.