Roofing Materials: Is Polymer Roofing Right for Your Home?
January 2, 2018 | Filed under: Roofing Materials
My experience in the specialty residential roofing industry goes back to the early 1980s when I was working summers during high school and college in the factory my father had started. I started working for the company, now Isaiah Industries, full time in 1986 and have never looked back. While we have always been a metal roofing manufacturer, we have always kept a close eye on plastic or polymer roofing materials, watching to see how viable that technology became over time.
We saw several attempts at large plastic roofing shingle panels in the 1980s. These products often utilized the GE Noryl resin which was still in its reasonably early years of commercialization at that point. None of these products did well. We saw issues with a breakdown of the plastic under ultraviolet light. We also saw issues with the large-scale panels not staying locked together on the roof, especially if there was any unevenness at all to the roof’s surface.
Recent years have seen more and more (plastic) polymer roofing and rubber roofing shingles, slates, and shakes come to market. My opinion remains “buyer beware” of these products. Yes, I have a certain partiality for metal roofing that has been time-proven for even hundreds of years at this point. However, I do respect the unique beauty of the polymer products and how appealing they can be.
I think we will all agree that when that severe storm rolls through our neighborhood at 2 a.m., we care more about the performance of our home’s roof than how pretty it is.
So, for that reason alone, for homeowners who might be contemplating a polymer roofing shingle, slate, or shake roof, I offer the following things for thoughtful consideration:
Polymer Roofing’s Ability To Conform To Your Roof
Most roofs, even new construction, have some bumps and lumps. Roof decks are rarely perfectly smooth and flat. Most polymer shingles available today go down in overlapping tiles. Unlike metal roofs, there are no interlocks between the tiles, top nor bottom. This means that, in areas where the roof deck is uneven, there is no way to conform the panels to the roof’s shape, which may cause unsightly gaps that are very vulnerable to weather intrusion.
Life Expectancy of Polymer Roofing
If I were considering these products, I would insist on seeing actual or accelerated weatherization test results going out to replicate at least 20 years, and preferably longer.
Watertightness of Polymer Roofing
Polymer shingles, having nothing but a large overlap, can be prone to water intrusion. Review installation manuals and videos on products you’re considering and assess the dependence that the system has on underlayment for water tightness.
Environmental Friendliness of Polymer Roofing
Polymer products are largely oil-based and also involve a decent amount of embedded energy for production. Additionally, the overlapping panels mean that raw material is used for significant portions of the roof system that are not even visible – a very inefficient use of raw materials. Most of these products also have no significant energy saving benefits.
Warranties for Polymer Roofing
When I read the warranties of most of these products, I walk away wondering how much confidence the manufacturers have in their own products.
Here are some questions to ask as you review the warranties on these products:
- Does the warranty cover product failure other than leaks?
- If it only covers leaks, is every leak covered or just certain ones?
- Does the wind warranty cover gusts that are potential in your area?
- Does the wind warranty go away over time?
- Does the warranty carry a maximum dollar value of coverage?
- Can the warranty be transferred and, if so, how many times?
- How does the warranty interact with insurance claims?
- Is the warranty prorated over time and, if so, what is the proration schedule?
- What limitations are on the warranty – what would void the warranty?
- Does the warranty provide materials only or materials and labor in the event of failure?
Polymer Roofing Alternatives
Again, I say all of this with no apologies for the appreciation for the time-proven beauty and benefits of metal roofing. Also, I want to stress that, with any roof system, proper installation is critical. However, as an industry veteran, I have significant concerns about the polymer roofing shingle, slate, and shake industry … and I encourage homeowners to be very careful in their diligence. Hopefully, this article helps you to that end.
Todd Miller has spent his entire career in the metal building products manufacturing industry. He is president of Isaiah Industries, an organization recognized as one of the world’s leading metal roofing manufacturers. Todd is currently Vice President of the MRA (Metal Roofing Association) and a Past Chair of MCA (Metal Construction Association). Through his website, he strives to raise the bar on standards and practices to provide property owners with the best possible products for successful roofing projects.
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How are your roof panels fastened and how much overlap?
Will the fasteners screws extend through the old 3 in 1 shingles and the 3/4 inch board sheeting?
My company manufactures primarily various “modular” metal shingles, slate,and shake products. We also manufacture a couple of styles of traditional vertical seam metal roofing. All but one of our products has concealed fasteners. The fasteners are often nails but can be screws. The amount of overlap varies from product to product gut generally is 1″ or so to cover the fasteners. Yes, the fasteners employed are chosen to be long enough to extend through the old roof if it’s still in place. Our testing has been done with fasteners of adequate length to penetrate the roof deck but if that is not desirable, we can often select fasteners that go well into the decking but do not come out the back side. I hope this helps. Please contact me anytime.
I live in an area with heavy snow. I currently have a metal roof and the roof has two large valleys. Every year the metal gets torn up in these valleys due to the sliding ice and snow. Do you have any ideas to get metal to work in these areas?
Thank you. I may have some ideas. However, before I provide some ideas that won’t work for your exact situation, can you send me photos but chance of your roof (with or without the ice damage) and also let me know where (approximately) you are located? Thank you. You can email me at todd@asktoddmiller.com