4340

Accredited to ISO/IEC 17025:2005

UKAS Accredited Company Registered in England & Wales No. 527550

Thermography for Roof Surveys

Thermography for Roof Surveys
Infrared thermography can be a very effective tool for roof asset management. Infrared thermography roof surveys are performed on roofs to quantify the extent of roof moisture (water) that is inside the roof system. Infrared thermography is not leak management. No matter how the water got into the substrate, the purpose of this type of survey is simply to establish where the water is located.

Extending the life of a roof will save the owner the expense and aggravation of re-roofing or re-covering. Re-roofing means that the roof is taken down to the decking and replaced completely. Re-covering means that the waterproofing layer(s) are removed, the wet insulation is removed and replaced and a new waterproofing layer is put down. The cost of an infrared roof moisture survey is tiny in comparison to repair/replace roofs, so knowing the exact location of the subsurface water is extremely useful information, since only those areas that are damaged need to be repaired. This information is used to plan budgets and when needed, as a bid document for contracting repairs and/or replacement of the roof.

ROOF MAINTENANCE IN GENERAL
The ravages environmental conditions such as sun, wind, rain, snow, chemicals, leakage, rapid changes in temperature and time - will eventually cause every roof to fail. Some roofs last 40-50 years if they are well-maintained, however they may only last 10 years if they are left and not checked.

Owners may believe that a roof warranty will somehow protect them from having to do maintenance. Not so, as roof warranties are written by roofing manufacturers for the purpose of protecting themselves from liability. For example, often a warranty is written so that if improperly installed or defective roofing materials are used on a roof and water leaks into the electrical switchgear room causing an explosion, the roofing manufacturer will replace the materials, the roofer will reinstall the materials, but the building owner has to pay for the replacement of the switchgear and any downtime that resulted from the failure.

Also, the roofer’s and roofing manufacturer’s liability, in the case of roof failures are also reduced by vaguely written roof warranties, which do not define words like "regular" or "routine" maintenance. Not accepting the roof warranty is not the answer, since the roof will not be installed unless the owner agrees to the warranty. To eliminate these problems, the building owner should have an agreement with a qualified roofer or roof consultant to inspect and maintain the roof (in accordance with the terms of the warranty) at least once a year.

Roof problems usually manifest themselves in two ways: Leakage and entrained moisture contamination. Leakage is pretty simple, although the leak inside the building rarely directly relates to the exact spot on the roof, since the water flows down the slope of the roof to a spot that is not sealed and into the building at that point.

Most leaks occur where the waterproofing is sealed or where there is a penetration of the roof. Since most types of roof systems absorb some amount of water, it is harder to find the exact spot of water contamination in the insulation because it may not leak into the building until it has absorbed all the water it can hold.

BASICS OF INFRARED ROOF MOISTURE SURVEYS
Some roofs and insulation types or combinations do not absorb any water. These roofs leak straight into the building. Even roofs which have insulation types that do absorb water, some do not exhibit a good infrared signal, primarily for two reasons.

• The surface is too reflective
• The roof’s ballast is so thick (or dense), that daylight radiation is not absorbed into the substrate (insulation), therefore it cannot be emitted back into the atmosphere at night.

Even with a strong infrared signal, factors on the roof can affect the analysis and interpretation of the data. Some of these factors: water between multiple layers, old patches, heavy flood coats, reflective coatings, heat-producing equipment under the roof –or heat blowing down onto the roof, stains, ponding water on the roof, heavy build-up of ballast at parapet walls and along edges.

WALK-ON INFRARED ROOF SURVEYING
To perform a walk-on or on-roof survey properly an experienced infrared thermographer and an experienced roof consultant or roofer and the building owners' representative for access and security should be present. The crew walks around the roof/s and when an area of suspect moisture is found, the roof consultant verifies it is wet and then the helper marks the edges of the area directly on the roof with marking paint as instructed by the thermographer.

The crew needs authorization and access to all areas and levels of the roof/s from either ladders or roof hatches and plenty of time to collect data. The infrared images are stored on videotape or digital media and printed. After these have been dispersed to the relevant people the remedial works can take place.

Figure1: Infrared Image of a Roof survey

CONCLUSIONS
Roofs are often replaced because know one knows where exactly the roof is damaged until it is too late. If you want your roof to last, it must be regularly maintained by professionals. Infrared thermography roof moisture surveying is the best method of non-destructive testing on roofs.

Please download our thermography maintenance check-sheet, please fill this in and e-mail it back and we can set up a maintenance schedule to suit your requirements.

Why Infrared Thermal Imaging Surveys
In summary its main benefits are:

• Quick inspection.
• Results easily shown in pictures.
• Shows location of air leakage.
• Shows thermal insulation defects.
• We use the latest detection equipment with fully trained personnel to achieve reliable results in the most demanding building applications.

We carry out many surveys each year and guarantee to offer a professional, reliable, and helpful and offer competitive pricing. We offer a last minute service at no extra cost, and we also undertake weekend Infrared thermography surveys on both on Saturday and Sunday in order to meet your out of hour’s survey requirements.

We offer a nationwide service offering a single supplier for all of your regional offices and projects.
Most of our clients, who use us for the first time, continue to use our services because of our proactive approach, this has led to nationwide agreements with many the top UK Companies, which allows them to benefit from even more competitive rates as well as unrivalled service.

We also offer other specialist testing and reporting, such as:

• Air leakage Testing to Dwellings and Commercial Buildings
• Fire Enclosure Testing
• Sound Testing
• Energy Performance certificates, EPC, SAP & SBEM

APT Thermography - Further Information

If you have any questions or queries please don’t hesitate to contact us:

By Mobile - 07967 233836 (available 7am to 10pm)
By E-mail - info@aptthermography.net