Infrared Roof Moisture Surveys in San Marcos, TX

Infrared Roof Moisture Surveys

Trapped water is the quantity that moves a roofing budget more than any other, and it cannot be seen from the surface. Insulation under a clean-looking membrane can be saturated across a third of the field, or bone dry under a roof that looks tired. A moisture survey turns that unknown into a drawing and a number. For a facility director in San Marcos, TX deciding between repair, recover and replacement on a low-slope roof, it is often the most useful money spent before the bid.

We combine infrared scanning with core-cut sampling, because each one catches what the other misses.

How Infrared Finds Water

Wet insulation holds heat longer than dry insulation. After a sunny day, as the roof cools in the evening, saturated areas stay warmer than the dry areas around them, and an infrared camera records that difference. We scan at the right time, usually dusk or after dark on a clear day, and map the warm patterns against the roof plan.

Wind, cloud cover, standing water, surface debris and membrane color all affect the readings, so the scan is a lead and not a finding. Warm patterns that match known penetrations, drains and wall lines point to leaks, while patterns that look like ballast or patching are checked against the roof history.

Cores Confirm the Scan

At each suspect area we cut a small core through the membrane and insulation, check it for moisture with a meter, photograph the layers and then repair the cut. Cores also record the assembly: membrane type, insulation thickness and type, cover board, adhesives and deck. That information feeds the recover decision, since layers and moisture both limit an overlay.

We also cut cores in areas the scan says are dry, to test the boundary. A scan alone may overstate or understate a wet area, and a few well-placed cores keep the map honest.

The meter readings and photographs of each core go into the report as a table by location, so a reader can see the wetness profile through the layers: dry at the top, wet at the base, or the reverse, which says something about where the water entered.

The Map Is the Product

The report shows a roof plan with wet areas outlined, core locations numbered and each core's findings recorded. We state the wet area as a share of the roof section so the owner can see whether a cut-and-replace repair is practical. Small, isolated wet areas near a leaking detail are repaired. Wide, connected wet areas point to a failed assembly that a replacement should address.

That share feeds the cost comparison directly. Wet insulation is removed and replaced in either approach, so a survey that gives the quantity lets the bid carry a real number and not an allowance.

The survey ends with a recommendation tied to the findings. If wet insulation is limited, we propose a cut-and-replace repair and a re-scan date. If wet areas are extensive but the deck is sound, we price a tear-off and replacement of the insulation with a new membrane. If the assembly is dry and the membrane is aged, a coating or overlay may fit the capital plan. In each case the proposal lists the quantities of insulation to be replaced, so the cost line follows measurement and not assumption.

Owners who carry the survey into their budget cycle usually find it cheaper than the surprises it prevents.

The proposal then names where each answer came from, so the owner can show a lender, insurer or board why the roof is on the list.

What Can Fool a Scan

Several roof conditions mimic wet insulation on an infrared image. Ballasted areas hold heat differently from the rest of the roof. Patches and double layers of membrane change thermal mass. Standing water cools or warms on its own schedule, and a roof with a reflective coating can mask the contrast entirely. Metal roofs and fully adhered systems over concrete decks behave differently from mechanically attached systems over steel, and some assemblies simply do not suit infrared at all.

For that reason we review the roof history and the assembly before scanning and tell the owner when infrared will not give a reliable answer. In those cases we rely on a grid of core samples or on electrical moisture meters, which cost more per answer but produce one.

Where Surveys Pay Off Most

Surveys pay off on large low-slope roofs where a mistake in the quantity of wet insulation is expensive. That includes warehouse and distribution buildings like those along the Kyle logistics corridor, where Hays Commerce Center is a 108-acre development on the west side of I-35, and big-box and outlet retail buildings east of I-35 in San Marcos. They also pay off before buying a building, since an unexpected wet roof can change the value of a deal.

For due diligence we combine the moisture survey with a walk and a review of the roof records, so the buyer gets the condition, the moisture and the remaining service in one report.

After Hail, Look Under the Surface

Hail can crush insulation without breaking the membrane, and the damage may not leak for weeks. The May 9, 2024 storm dropped hail up to six inches across at Johnson City before moving on to San Marcos. A moisture survey after such an event finds water that has already entered and shows whether bruised areas have become wet.

The results support a hail damage assessment, because they separate storm-related moisture from long-standing leaks. They also give the owner a baseline for the next survey.

Timing and Repeat Surveys

A first survey sets the baseline. Re-scanning every few years, or after significant events, shows whether wet areas are growing. A stable small area can be left alone with a watch date, while an expanding one moves the roof up the replacement queue. We keep the maps from each survey so the owner can compare them directly.

Heat plays into scheduling. Hot Central Texas summers give strong thermal contrast on many clear evenings, and spring and fall nights often work as well. We pick the dates according to the forecast and the building.

Commercial Roofing Questions

Can I rely on the infrared scan alone?

Not for a repair or replacement decision. The scan shows temperature patterns, and cores confirm moisture and record the layers. Together they give a map that a bid can be built on.

Does the roof need to be dry for the survey?

It should be dry on the surface and have had sun earlier in the day, since standing water and cloud cover distort readings. We reschedule when conditions are poor and do not guess from a bad scan.

What happens to the holes cut for core samples?

Each one is patched with compatible materials and sealed the same day. The patch locations are marked on the roof plan, so they are visible in later inspections.

How does a survey help with insurance after a storm?

It documents moisture on a known date and separates storm-related water from older leaks. That distinction supports the claim and tells the owner which areas to repair first.

Will a moisture survey tell me how much of the roof to replace?

It gives the wet area for each section, which shows whether a partial replacement makes sense. A small cluster can be cut out and replaced, while connected wet areas often make a full tear-off the better choice.

Schedule a Scan and Cores

Tell us the roof type, age and any leak history, and we will plan the scan window, the core locations and the report format for your budget review.

Request a Roof Assessment

Related Roofing Work

Roof Recover and Overlay

A recover over a sound commercial roof can save tear-off cost in San Marcos, TX. We test for moisture and code limits and say when removal wins.

Roof Condition Reports

Written roof condition reports in San Marcos, TX with photographs, moisture maps and core results, sorted into replace, repair and watch groups.

Commercial Roof Replacement

Full tear-off and replacement for commercial roofs in San Marcos, TX, planned around building class, hail history, occupancy and the owner's budget year.