Courtesy Dicor Corporation
[Editor’s note: This information is provided by roof membrane manufacturer Dicor. While there’s plenty of “promotion” for their product included, some of the information and principles may be of assistance to our readers.]
Most people don’t think of the need for an RV roof to be flexible, but flexibility is a vital characteristic that every RV roof needs. Why is flexibility so important? The reason is simply that as an RV travels down a road it flexes. Whether it’s from going around a corner, or traveling over an uneven road, or coming to a sudden stop, your RV flexes. So your roof must flex, too, because if it doesn’t, it could start to crack and that could cause leaks. If you are thinking about putting a new roof on your RV or buying a used unit, read on.
Two significant factors that can affect a roof’s flexibility are colder temperatures and the roof’s age. Let’s talk about colder temperatures first.
All of today’s modern roofing membranes are flexible at moderate temperatures but will stiffen when it gets colder. Some membranes such as Dicor’s DiFlex II™ hold up better under colder temperatures than others. This was demonstrated by an independent third party testing certain membranes in what is known as a “Low Temperature Impact Test.” Sounds pretty scientific, don’t you think? Well, it is.
During this test, a six-pound hammer is brought down on a sample of material at a specified temperature. The sample fails if it shows any signs of cracking. DiFlex II TPO passed the test down to -60 F. Another membrane used in the manufacture of RVs roofs failed at only -20 F. Although it’s unlikely that anyone will be RVing at 60 below zero, this test vividly demonstrates just how flexible and tough the DiFlex II membrane is.
How might age affect your roof? Some RV roofs use a material that requires additives to make it flexible. These additives are called phthalate-based plasticizers. The common designations of these chemicals are: DEHP, DINP and DIDP. As the membranes that contain these materials age, these plasticizers will over time leach out of the membrane due to rain or exposure to the sun, causing the roof to become more brittle. If the roof gets too brittle, it becomes at risk of cracks from hail events. As hailstones impact a brittle roof, they can cause spiral or lateral impact cracks. DiFlex II does not contain any of these plasticizers and remains flexible throughout its lifetime.
Today’s roofing membranes are really marvels of chemistry, but like all things, they each have their own characteristics. So if you’re thinking about a new roof for your coach, consider DiFlex II. It’s one more layer of security and peace of mind. When you think about everything you have riding under your roof, that kind of assurance is an important part of your RVing experience.