Infrared and Core-Cut Moisture Surveys in Davenport, IA

The roof looks dry. The ceiling tiles say otherwise.

That is the usual start of a moisture survey. A membrane can look fine from the hatch while the insulation under it holds water from a leak that started two winters ago. An infrared scan and a handful of core cuts show where the water is and how much roof it covers. In Davenport, IA that answer often decides whether a building gets a repair, a recover or a full replacement.

Water gets into a roof at a flaw, such as a seam, a flashing or a puncture, and then it spreads sideways through the insulation. It does not drip straight down. It may travel dozens of feet before it finds a gap in the deck and shows up as a stain.

Meanwhile the wet insulation loses most of its insulating value, the fasteners rust, the deck corrodes, and each freeze-thaw cycle breaks it down more. Davenport records have swung from -29 F to 111 F, and a normal Quad Cities year brings more than 36 inches of snow. A wet roof in that climate gets worse every winter.

Infrared cameras read surface temperature. During the day the sun heats the roof. At sunset the dry areas cool quickly, while wet insulation holds its heat longer. The camera shows those warm patches as clear shapes.

That is why we scan in the evening after a warm, clear day. Conditions matter:

• The roof surface must be dry, with no standing water or fresh rain.
• The sky should be clear, and wind should be light.
• Sunshine earlier that day has to be strong enough to load the roof with heat.

If the weather does not cooperate, we reschedule. A bad scan is worse than no scan, because it gives a false answer.

Large roofs take more than one evening. A scan of a big plant or warehouse roof in the Eastern Iowa Industrial Center off I-80 may run over several clear nights, and the heat only lasts a few hours after sunset. We plan the route in sections, mark each one on the roof plan, and keep the crew small so the work stays quiet and safe on a dark roof.

Infrared points. It does not prove. Warm areas can also come from dark patches, thick insulation or equipment below, so we confirm with cores.

A core is a small round sample cut through the membrane and insulation. We check the layers, measure moisture with a meter, photograph the cut and then seal it with a patch that matches the membrane. We cut at suspect spots and at a few areas that look dry, to calibrate the scan. The results tell us which anomalies are really wet, and they show the roof makeup: membrane, cover board, insulation type and thickness, vapor retarder and deck.

The product is a marked-up plan of your roof. Wet areas are outlined, labeled and numbered, with core locations and photos tied to each. We estimate how much of the roof is affected and how deep the wetness goes.

The map separates what can be repaired from what cannot. A few small wet spots near a failed flashing can be cut out and replaced. Large wet areas spread across the roof usually mean the insulation needs to come off. A hands-on roof inspection goes with the map so you have the cause as well as the location.

The map is also a baseline. Keep it with your roof file. If a new leak appears two years from now, a repeat scan shows right away whether the wet areas grew or whether the new problem sits somewhere new.

With the map in hand, the decision gets simpler.

If the wet area is small, the plan is local repair: cut out the wet section and trace the water back to its entry point with a commercial roof leak repair visit. If the wet area is moderate and the rest is dry, the roof may qualify for a recover, with the wet sections cut out first. If the wet area is large, the cost of a full replacement is easier to justify, and the map helps you plan the budget for it.

Wherever wet board comes out, new roof insulation and cover board goes back in before the membrane is closed over it.

Not every roof scans well. Ballasted roofs hide the membrane under stone. Heavy gravel, thick coatings and some reflective surfaces blur the readings. Metal roofs and roofs with little insulation give little thermal contrast. Snow cover ends the scan for the day.

When infrared is the wrong tool, we use other methods: capacitance or nuclear meters, probes, or just more cores. We also use a drone roof inspection to get a wide view first on large roofs. We tell you which method fits your roof before we price the survey.

Survey timing affects what the image can tell us. The roof needs a useful temperature difference between wet and dry areas, and stored heat, cloud cover or recent rain can blur that contrast. We compare the thermal pattern with a matching visual image and confirm selected anomalies with a core or other accepted test before recommending removal. The deliverable marks tested points, not every color change, so a bid can quantify wet insulation without treating the whole roof as compromised.