Note: This guest post is by Steven Thomas. As president and owner of Roof Leak Detection Company, Inc., Steven Thomas has evaluated over 20,000 roofing systems on commercial, industrial, and residential properties, and has been qualified in court as an expert regarding roof testing and evaluations. His company is an approved Testing Laboratory and has held this certification since 1994.
After a major loss, it is very important to inspect your property, especially your roofing system and rooftop components. Your roofing system is the most important facet of the structure, and proper analysis of the storm for damage should come first. Low-slope roofing systems are particularly susceptible to the effects of wind uplift. Immediate inspection is required, and the inspection should be by a trained, certified, and objective professional.
So, what does proper inspection look like? A detailed inspection of your low-slope roofing system should include both a visual and physical analysis of all rooftop components. Sometimes damage may be obvious and sometimes not. What should the inspector look for?
First, safety should be the most important part of the inspection. Damaged components may be concealed. This could include the substrate, which may have been compromised. So, making sure where you walk should be considered first. Using marking paint will also help identify safety hazards as well as damage for follow-up analysis and repair. As you’re performing your visual inspection, you should document the conditions photographically. This would include the obvious and sometimes the not-so-obvious.
Obvious types of wind uplift damage typically include material displacement, as well as blow-off. Fasteners may be backed out, and insulation deflected. Backed out fasteners will create tent like conditions. Care should be taken not to walk on these damaged components. These areas should be marked and documented.
Consideration should be made for collateral damage. This would include flashing rooftop units, as well as debris strikes. Loosened condensation line conduits and flashing could have become a whip during the wind event and become projectiles during the storm. This could impact the performance of the RTUs, as well as damaging the roof surface. Document conditions photographically.
Windborne debris could come from dislodged roofing components or from aerial debris. This debris can gouge, impact, and penetrate the roofing system. Granular loss, as well as gravel displacement, may occur. High winds will scour granules and gravel, leaving bare spots. These bare spots often become irreparable and can cause deterioration of the membrane. Wind can disrupt the gravel retention on this roof and can leave the roof membrane exposed to direct UV sun rays, which will rapidly deteriorate the roof and negatively impact drainage. The granules and gravel are essential to protect the built-up roof membrane from exposure to destructive UV sun rays. The absence of granules will greatly reduce the service life of these roofing systems. As a long-term condition, it can reduce the service life of the roofing system by 50%.
If the bitumen is displaced and exposes the scrim, the waterproofing element has been decreased from the manufacturer’s original intended bitumen thickness, which decreases the overall estimated service life of the roofing system. Bare spots caused by wind-scoured gravel will expose the built-up plies to UV sun rays and result in rapid deterioration. Reapplying the “grit or coating” can only be considered a topical repair, as it does not increase the bitumen back to the original thickness in these damaged locations. Wind-scoured gravel also affects drainage, and simply sweeping loose gravel back into position is well intended, but not permanent.
Single ply TPO roofing systems are also highly susceptible to wind-borne debris damage and material deterioration. Windborne debris impacts to the TPO roof membrane will remove portions of the polymer coating. The polymer coating is an essential waterproofing component of the TPO roof membrane. The removal of the top layer of polymer from debris impacts will only worsen over time as the impact area is exposed to destructive UV sun rays. The polymer coating is white, and the underlying fabric is darker than the white surfacing, the exposure of the underlying component of the TPO membrane will require a repair, however it is our opinion that applying dozens of patches to a roof is not a reasonable repair.
What if the roof is wet? A leak may be observed on the interior or maybe not. Wet roofing materials are concealed and often materialize as a stain either quickly after a loss or long thereafter. The inspection must include a moisture survey. This nondestructive test will identify wet roofing materials and give the building owner an effective tool to guide repairability versus replacement. Wet roofing materials can sometimes be mitigated topically, but more often than not lead to irreparable conditions, which will lead to a complete removal and replacement of all roofing materials. Effective test methods such as infrared thermography, electrical impedance, and nuclear radioscopic moisture testing by a certified and licensed roof testing firm is strongly urged. Wet roofing materials and insulation is functional damage.
Proper consideration of whether the roof could be repaired or if total replacement is warranted. Damage may be directly visible or concealed on a low-sloped roof. Material displacement and moisture intrusion into the roofing system is not the only measure of damage on a low-sloped roof. Consideration as to how to repair withdrawn fasteners, debris impacts, and gouges to the roof membrane and how that affects the remainder of the roofing system must be considered as well. Consideration should also be made on whether the repair would be warranted by any roofing manufacturer. Although repair methods such as patching and backlaping are common, they become a constantly maintainable area of the roof and will eventually compromise the serviceable life of the roofing assembly.
Even though a small scrape or gouge may seem inconsequential, it may lead to moisture infiltration and material degradation. Repairability also becomes highly important to consider. How does the building owner address bare spots and countless scrapes and gouges to their roofing system? Hundreds of patches are not practical. Simply adding more granules and gravel is not a viable solution. And depending on the size of the cut scrapes, impact, gouges, and bare spots, reroofing may be a cheaper alternative. An untrained professional may consider these types of damage cosmetic and lead to improper and misguided repair. Proper inspection by a certified roof inspector is urged.
CONCLUSION: Swift action and due diligence are key to protecting your structures’ most important asset. The roofing system protects everything on the interior. When functioning properly, it provides many years of waterproofing and security. But after a loss, it could lead to greater material and financial loss. Have your roof inspected by a professional. Make sure the professional is certified. Document all conditions. Act immediately before conditions become irreparable. Be responsible and protect and manage your most important asset.
(NOTE: Roof Leak Detection Company, Inc., is NOT a roofing contractor nor do we sell any roofing material. We are a licensed and certified Engineering and Roof Testing Firm specializing in Forensic Roof Evaluations.)
