Why Use a Reinforcement Sheet in Roof Repairs and Restorations
The best practice for commercial roof repairs and restorations should include a reinforcement sheet or scrim in combination with a coating or cement. For roof repairs, the area being treated will generally receive an application of coating or cement, followed by the reinforcement sheet, then topped with another application of coating or cement. This is known as a three-course application. In some instances, an additional layer of reinforcement and coating/cement is needed, making it a five-course application. For roof restorations, a base layer of coating is applied, then the reinforcement sheet is embedded into the coating. One more layer of coating is applied over top and depending on the roof and longevity of warranty desired, additional layers of coating can be applied. A reinforcement sheet is generally made of polyester but can also be hybridized with other materials.
There are several benefits to utilizing both a coating and a reinforcement sheet vs. just a standard coating or liquid-applied material.
Tensile Strength
Most importantly, the reinforcement sheet or scrim imparts a high tensile strength to the roof section being treated. This will help resist splitting or cracking. While most roof coatings have just enough elongation to beat minimum codified requirements, it is not enough to accommodate movement on the roof or substrate failure. The substrate is the membrane layer under the coating being applied. Eventually, the polymer will fatigue and crack or split. The reinforcement scrim prevents this from happening. In addition, the high tensile strength of the reinforcement scrim will help the long-term performance of the roof, resist wind uplift, and accommodate any stresses or strains. The reinforcement scrim also adds tear strength and puncture resistance to the roof to defend against hail, debris being blown across the roof, and even equipment and foot traffic damage.
Ponding Water Protection
In areas of the roof with ponding water, including a reinforcement scrim is even more important. The standing water accelerates deterioration of the roof surface so having the extra protection of the reinforcement sheet can help slow this aging down.
Dimensional Stability
An application of coating alone will move quite a bit as the roof heats up and cools down (expansion and contraction). Adding in the reinforcement sheet will help keep the treatment together and contribute to the dimensional stability.
Flashings Treatment
One of the most common areas of roof leaks is the roof flashings. Incorporating the reinforcement sheet into the repair method makes for a smoother surface and transition from vertical to horizontal. The water will flow along it and drain off the roof. Using coating or caulking alone can create pockets that accumulate water, causing even more issues down the road.
Warranty Protection
Substrate failure is an exclusion in some roof restoration warranties. This means that if the substrate or roof membrane below splits or cracks and causes the coating to do the same, it is not covered under the warranty.
Most roofs are restored because the substrate is failing, creating the need for reinforcement and repairs. The use of a reinforcement sheet combined with the coating application can eliminate the substrate failure clause as an exclusion to the warranty.
The Simon Difference
While the industry is catching up to this reinforcement methodology, Simon Roofing has been using this application in repairs and restorations for years. Our technicians are thoroughly trained and extremely familiar with the best application methods for embedding the reinforcement scrim into repairs and restorations.
Our proprietary reinforcement sheet was specially developed to complement our coatings and cement products. Our coatings have high elongation properties compared to others. Marrying a high elongation polymer with a high tensile strength scrim creates truly superior commercial roof repairs and restorations.
