Core Cuts and Meter Readings
Every thermal anomaly is checked. We take readings with a moisture meter across the roof, and at representative locations we cut a small core through the membrane and insulation to look at the layers directly. A core shows the number of layers, the type and thickness of insulation, its condition, and whether water is present, none of which a camera can see. It also tells us whether the roof has already been recovered.
Each core is patched on the spot with a proper repair, with the membrane lapped and sealed, so the survey does not leave new weak points behind. Where a core is made through a roof with a warranty or manufacturer requirements, we follow the written method for patching it. The record of each core, with a photograph and location, becomes part of the report, so an owner can see what was found beneath the surface.
Marking the Roof and Mapping the Wet Area
After the scan and the cores, we mark the roof itself with the outline of the wet areas, using paint that can be seen from the roof or by drone and will wear off naturally. The marking lets a repair crew cut out only what is wet, lets a replacement estimator measure the true affected area, and lets the owner walk the roof and see the findings first-hand. We also draw the same outlines on a roof plan with numbered locations.
The report then states how much of the roof is wet and where, which areas are dry, and what each finding means for the next step. A small, localized wet area leads to a cut-out and repair. A wide wet area points to replacement. Dry roofs with aging membrane may be candidates for a recover or a silicone coating. The map is the basis for that decision and for comparing options on equal terms.
Conditions That Spoil a Scan
Not every roof can be scanned well. Heavy gravel ballast, thick reflective coatings, pavers and planted areas mask thermal differences, and a roof that has been rained on within the last day or two may show water on the surface that confuses the image. Metal roofs and fully adhered assemblies with little insulation respond differently. We tell the owner before the survey if a roof is a poor candidate, and we may rely more on meter readings and core cuts in those cases.
Wind and cloud also matter. A breeze cools the roof unevenly, and a cloudy day gives too little solar loading to produce a strong contrast. We reschedule rather than force a weak scan. February is the wettest month in Pasadena, with about 3.9 inches, so surveys in winter depend on the right weather window, and we favor late summer and fall, when conditions are most reliable.
What the Survey Settles
The survey exists to answer a business question. A commercial roof replacement is a major purchase, and an owner should not make it on the strength of a few leaks. If the survey shows isolated wet areas, repair is usually the better choice. If it shows widespread saturation, the money spent on repair is better saved for replacement. Either way the finding rests on cores and a map, not on opinion.
It also supports transactions and planning. A buyer or lender looking at a large retail property, the kind of building that the 456,000 SF IKEA in Burbank and the Galleria in Glendale represent, wants to know how much of the roof is wet before agreeing on price, and the same method carries into due diligence roof surveys before a purchase. On roofs that large, scanning saves the most time, and a drone roof inspection can cover the edges and high areas without a crew crossing every section.
Commercial Roofing Questions
How accurate is an infrared scan by itself?
It is a strong screening tool but not proof. The camera shows temperature differences, and several things cause them, including thicker insulation, equipment below the roof and trapped water. That is why we confirm with meter readings and core cuts. The scan tells us where to look, and the cores tell us what is there.
Does the survey damage the roof?
The scan does not touch the roof. Core cuts do make small openings, and we repair each one immediately, sealing it so it does not become a leak. Where a manufacturer sets requirements for patching cores, we follow them. A properly patched core is a small, controlled repair compared with the cost of a wrong decision about the whole roof.
Which kinds of roof can be surveyed?
Most low-slope roofs with insulation can be scanned, including single-ply, built-up and modified bitumen systems. Results are best when the surface is clean, dry and unshaded. Ballasted, heavily coated or paved roofs are harder, and metal panel roofs need a different approach. We tell you in advance how well your roof is likely to scan.
When should I order a survey?
Before spending money on a recover, a coating or a replacement, because the survey tells you which of those the roof can support. It is also useful before buying a building, after a storm or fire, and when repairs keep recurring in the same area. A baseline survey gives you something to compare against later.
How long before I get the findings?
Scanning is done the evening of the visit, and the cores are cut and patched while we are on site. Written findings with the moisture map and core records follow after we process the images and measurements. If you need to make a quick decision, tell us, and we will give you a verbal summary at the end of the visit.
