Commercial Real Estate – Flat Roof Repair and How to Make them Green
Installing a new flat roof or repairing your existing flat roof in the winter is possible; there are a few things to know before you decide to go ahead.
The first thing to clarify when speaking of winter installations is temperature. We will consider anything under 4 degrees Celsius winter for arguments sake. It is a great time of year to replace or repair your leaking flat roof as you will get the best prices, as well as a greater selection of the best roofing contractors, as work is limited and many contractors will lower their prices to compete for work. However, some roof systems can’t or should not be installed in colder temperatures.
In the winter, many of the glues and adhesives used to install single ply roof systems like EPDM, Cold process Modified Bitumen, or any type of Peal-and-stick flat roofing products can not be installed correctly as many of them will not bond properly in cold temperatures. This will cause premature failure, which will surely cause leaks in the spring. Rubber roofs like EPDM are usually installed with different types of adhesives. Manufacturers of this type of roof system recommend not to install in temperatures bellow 4 degrees Celsius.
There are some contractors out there that insist that these rubber type roofs can be installed in the winter, by pre-warming the glue and only working when the sun is out, to warm up the black rubber membrane, for better adhesion. Keep in mind that some sales reps will encourage contractors to install these rubber roof systems in the winter, because they make commissions and roofers will install these systems because they need to have jobs coming in to pay their bills, there is no concern about violating installation specs. This type of practice only hurts the customer in the end. Because there is limited work to go around in the winter and because these installers have to lower their normal rates, eating up the initial costs of supplies, many of these contractors will cut corners to make a profit. What you then get is a roof system that was installed incorrectly or outside of manufacturer’s specifications, frustrated roofers installing it, and potentially frozen adhesives and glue which will most likely result in roof leaks in the near future. Any warranty claims would likely be denied by the manufacturer because this type of roof was installed incorrectly. If you do decide to go with an EPDM system do not install it in the winter.
There are, however, two other single ply systems, TPO and PVC, which are thermoplastic single ply products that can be installed in the winter. They can be installed in the winter because they use Hot Air Welded seams instead of an adhesive. Both PVC and TPO are attached to the roof deck using mechanical assembly with heavy duty screws and plates, and all seams are sealed using Hot Air welding equipment which usually operates at 800-1100 degrees Fahrenheit. Such high temperatures ensure that even during cold winter months, all seam welds will not be affected. One thing to remember about single ply roof systems is that they are just that – Single ply, meaning that there is only one chance for Mother Nature to get in. Over the winter months many roofs will have ice build up which may cause damage over time by the constant movement of the roof and ice. The best defense against Mother Nature is to not have any seams at all.
Torch applied modified bitumen is another roof system that can be applied in the winter but the manufacturers specify certain application techniques to deal with low temperatures.
The modified bitumen rolls get stiff in cold weather, they need to be rolled out and relaxed in the sunshine before rolling them back up and installing them.
Torch applied roofs can cause roof fires with the use of large open flame torches on the roof. This is why insurance is very expensive for the torch application roofer.
Hot asphalt or BUR roofs (built up roof) systems are the ideal flat roof to be installed in the winter. There is no open flame on the roof. Liquid tar or asphalt is pumped up to the roof where it is applied. The hot asphalt or tar is very easy to work with as it is heated to over 400 degrees in hot kettles. Hot asphalt is a liquid so it seeps into every crack and crevasse, when the asphalt cools down it causes a watertight seal. Asphalt roof systems use tar paper or other reinforcement materials in between the asphalt layers.
Some high performance hot applied roof systems use rubberized asphalt to aid in the stretch the roof system needs to perform in ultra low Canadian winter temperatures.
Because the materials are pre-heated, the hot asphalt roof system becomes the most reliable cold weather roof application system. Multi layered hot asphalt roofs like TOUGHROOF, use an ultra white, highly reflective coating to minimize UV exposure to the asphalt underneath, making the roof last much longer. These types of “cool roofs” are the future as they do not contribute to the Urban Heat Island Effect.
When it comes to winter time flat roofing the hot asphalt roof is the best purchase.
Other systems may be installed in the winter, but the hot asphalt system does not need application technique adjustments to successfully install the roof system. The hot asphalt roof system has been around since the dawn of the industrial age and still to this day out performs all other roofs systems.
Remember when choosing a flat roof system do your homework. All flat roof systems are NOT created equal.
By Dan Sheridan and TOUGHROOF