By Dana Howell
This article is reprinted with permission from Properties Magazine.
Does your building have a flat roof that has been a constant problem? Do you find yourself making what seems to be never ending repairs to your flat roof? Are you convinced that there is no flat roof out there that doesn’t leak? Do you find yourself asking the question why would anyone construct a building with a flat roof? All these questions/concerns are legitimate flat roof questions.
Let’s start at the beginning. Why would you build a structure with a flat roof? There are actually many reasons, but the main reason is space. A flat roof supported by columns gives you a much larger floor plan, typically seen in banquet halls, strip malls and warehouses.
Now we understand one reason these structures are built, but what causes them to be a constant problem keeping them from leaking? Again, there are many factors, but at this time I would like to focus on just one: movement. Any time you have temperatures that fluctuate as they do in the Midwest, you will experience movement. With this being said, if your flat roof is not able to withstand movement you experience failure. This is why splitting and cracking can often be seen.
A great solution to this problem was the invention of single ply roofing. Single ply roofs are roofs that protect a building through one layer of roofing membrane as opposed to the old multi-layers of tar felt and gravel. Two popular types of single ply roofing in our region include rubber (EPDM) and roofing materials containing plastic compounds such as PVC’s (Poly Vinyl Chloride). These membranes are able to move more freely to take on the expansion and contraction often seen in large buildings.
The trend in flat roofing is clearly moving toward the single ply roofing systems over the multiple ply. Single ply roofing has been on the increase for many years while multiple ply roofs have been seeing a significant decrease in the market shard of flat roofing.
Rubber was the dominant single ply during the 1960s through the mid 1980s. Rubber is installed several different ways. Some are installed by overlapping the sheets of rubber and covering them with river rock called ballast. Others are glued or screwed to the deck. The seams are then glued together with the hope of providing a long lasting water proofing solution. The major problem associated with rubber roofs is de-lamination. De-lamination is the breaking down of the glue or adhesive that holds the sheets of rubber together.
Heat welded roofs are made of plastic compounds such as PVC. Heat welded roofing systems are the fastest growing portion of the single ply roofing industry. The welding together of PVC sheets at the seams provides a permanent and stronger bond than glues or tapes. The Duro-last Corporation in Saginaw, Michigan actually pre-welds sheets of membrane up to 2,500 square feet in their factory, thus most of the seams of a deck sheet are welded under ideal conditions.
For more information, call Damschroder Roofing LLC at 888-307-2785 or visit www.damschroderroofing.com.