Why Perform an Infrared Roof Moisture Survey?

Midwest Infrared utilizes remote thermal sensing for the detection of wet and/or deteriorated roof insulation. The final results give you an "x-ray" of your roof, locating all areas of wet insulation. To better understand why we look for wet insulation, the following is a review of insulation purposes and hazards.

The five major purposes of insulation are:

1. To control temperature

2. To prevent condensation on the interior of the building

3. To provide a better substrate for roofing felt application

4. To prevent thermal movement

5. Relieve stress in the roof membrane

Wet insulation does not insulate as effectively as dry insulation. Because water has a higher thermal conductivity than any type of roof insulation, heat flow is greater through wet insulation. In the wintertime, the heat flow is from interior to exterior and in the summer time the heat flow is reversed. Wet insulation increases that heat flow, thereby, increasing heating and cooling costs.

Interior surfaces are kept warm by insulation on the roof deck. However, when the insulation is wet, and has lost it's capacity to insulate, interior surfaces become cooler and are more susceptible to condensation. Condensation can be a hazard to the interior structure and equipment.

When insulation becomes sufficiently saturated it begins to decompose. The built-up roof membrane may then collapse along with the insulation. Wet insulation does not serve as a good substrate for roofing membrane, whether it's a single ply or built-up roof assembly.

Once the insulation is wet and there is a vapor barrier, the water cannot escape, but proliferates through the dry insulation due to expansion caused by solar radiation. On sloped roofs, the moisture within the insulation moves by the force of gravity. In any case, if the cause of the wet insulation is not discovered, the problem not only spreads but also worsens in intensity.

Trapped water in the insulation expands with higher solar radiation, delaminating the roofing felts and degrading single ply lap joint sealants, forming blisters and creating fractures and holes. The trapped water causes the insulation to buckle, warp, decay, and some insulation to simply breakdown. Damage to the roof deck takes the form of rusting steel decks, rotting wood decks, and spalling concrete decks.

In summary, wet insulation not only doesn't serve the purpose for which insulation is designed but also poses a serious threat to the entire roof system.

When to Perform an Infrared Roof Moisture Survey?

A. The insulation being installed wet.

B. Condensation within the roof system.

C. Moisture vapor from within the building.

D. Leaks in the roof membrane or its components, i.e., flashings, gravel stops, vents, ventilators, expansion splits, copings, and etc.. Roof leaks probably account for 90% of all wet roof insulation.

In the past, insulated roofs were examined either by cutting holes into the roof or using a moisture meter. These necessitate the cutting of many holes into the roof membrane, which can cause future leaks. The more probes cut into the roof membrane, the more thorough the analysis and the greater the possibility of leaks; conversely, the less probes made, the less reliable the analysis. Either way, this process is time consuming and the results are inconclusive.

The Midwest Infrared Roof Analysis is a system, which pinpoints those areas of wet insulation through the sensing of thermal radiation emitted from the roof surface. The analysis includes 100% of the roof area being surveyed. What previously required many costly hours and many cuts into the roof membrane to determine the extent of wet insulation can now be accomplished precisely, quickly, and economically.

What may be most important in the analysis is that sound roofs can be identified as well as problem areas. Un-necessary tear-offs can be prevented and work concentrated on the problem areas affording the customer large savings. Analyzing your roofs on an annual basis will insure small problems are caught before they become major headaches for all. The cost of an infrared survey is a fraction of the price of a roof replacement project.