So you have a lifetime dimensional shingle on your roof, and after 15 years, your insurance company is giving you 60 days to replace your shingle roofing, or they will cancel your policy. Why? Your roof appears to look good from the ground and is not leaking. I have been on a lot of roofs in this situation, especially in the last couple of years. Most of them look like they could last four or five more years. They definitely will shed water and keep the house dry. So why would the insurance make you replace your shingle roofing at this time?
With about 1/3 of these roofs that I have inspected, the sealant strip shows signs of failure. There are several studies that have been done in hurricane-prone areas that do substantiate this determination. One such paper titled “The influence of unsealing on the wind resistance of asphalt shingles” (Science Direct, Journal of Wind Engineering and Industrial Aerodynamics, Vol. 130, July 2014, Pages 30-40) addressed the tearing and blowing off of shingles due to wind.
Field studies in Florida and Texas indicated that the sealant strips of asphalt shingle roofing can lose adhesion along the leading edges over time. The asphalt shingles are then partially unsealed and more likely to blow off or tear during a wind storm.
That is the reason your insurance company does not want to cover a roof older than 15 years. A strong category 1 hurricane would probably do enough damage that your insurance company would then have to pay to replace the entire roof. Due to the extreme weather conditions here in Southwest Florida, a lifetime dimensional shingle will likely only last 18 to 20 years. Sealant strips on some brands of shingles seem to hold up better than others. This is also true of secondary water barriers. Some brands of peel-and-stick underlayments lack flexibility. The flexibility is what creates a seal around the fasteners to prevent a leak.
To ensure your shingle roofing has the best chance to survive a hurricane, I put together a roofing system that is made up of the best quality materials. Cutting corners in materials is not part of my system. Ventilation plays an important role as well. Without proper ventilation, the sealant strip on shingles will deteriorate at a faster rate. This is why I use a ridge vent on my jobs to provide uniform ventilation to the roof.
If you’re interested in learning more about this and would like a free estimate, contact me today and I’ll be happy to be of assistance!