A recent GAF report, “Asphaltic Roofing in Contact with non-Compatible Building Components and Roofing Accessory Products,” should be read by any homeowner with an asphalt shingle roof – and that’s most of us. The report addressed the issue of oils present in asphaltic roofing materials and the fact that they may not be compatible with plastic roofing accessory products. Those plastic products can include a gutter guard, since plastic is a common component of many common curve, filtering, sponge or DIY products readily sold today.
Not all building materials are designed to be in close contact with each other. The GAF report notes:
- Oils in asphaltic roofing materials can migrate onto some plastic materials such as gutters or plastic-based leaf filters and cause staining and softening of the plastic.
- The leaking oil can result in the failure of the plastic product.
- Plasticizers and other additives in plastic materials can also affect the asphalt. If they migrate into asphaltic roofing products this can result in the softening, dripping and flowing of the asphaltic products.
- Leaks can result “as the asphaltic materials and incompatible components deteriorate and prematurely fail.”
What to do?
If you are a homeowner with an asphalt roof and you want to install roof accessories such as a plastic leaf filter, now is the time for due diligence. The GAF report recommends that you “use building components and accessory product designed to be compatible with asphalt roofing.” Read the product literature for information about the components. And if in doubt, “contact the manufacturer of the building component or roofing accessory to confirm the product has been formulated to be suitable for use in contact with asphaltic roofing products.”
In the case of most gutter guard products, we believe most manufacturers are not aware of what the GAF report implies and have done no tests to confirm suitability. The most important thing is not to believe what a local company and the salesperson that will show up on your doorstep for an estimate might say; they’re not the manufacturer. They typically do not have detailed information like this available to them and will focus on selling you their product by not presenting all the facts.
If you believe your asphalt roof may have been damaged by incompatible plastic components, you may want to have the roof’s integrity checked for signs of softening, flowing or dripping. A GAF Master Elite Roofer, who has met certain qualifications to earn this distinction, would be a good reference for this review.
If you are a homeowner with a classic asphalt shingle roof considering installing a plastic leaf filter, the team at MasterShield recommends you look into installing a gutter guard
constructed from aluminum, no different than your existing aluminum gutters, with which GAF notes no issues. Additionally, a gutter guard containing a surgical grade stainless steel micro mesh will provide better performance, particularly if its a product from multi-patented Alex Higginbotham. Surgical grade stainless steel has no lasting issues with these leaching elements: high quality filters like the proprietary one in our MicroVortex micro mesh are commonly used for industrial filtration, including filtering acids.