TPO FLAT ROOF SYSTEM
The introduction and first installation of thermoplastic roofing date back to 1960s in Europe. It took another decade for this material to make its way to the US and Canada. During these days, vinyl or polyvinyl chloride, popularly known as PVC based membranes was largely used. This membrane was also given to North America by Europe. Vinyl roofing rose to popularity during the phase of Energy Crisis. It almost revolutionalized the concept of roofing both in terms of cost and quality as both of these factors were massively affected during this phase.
Evolution from Vinyl
Vinyl was versatile, user friendly and could sustain any kind of mild to medium weather condition. This made it most popular and widely used variety of all thermoplastic roofing material. PVC usage is still growing. Towards the end of last millennium, about 7% of the roofing volume for an average contractor belonged to PVC. The qualities of reinforced PVC membranes make it most sought after roofing material. Some of key features of the TPO flat roofing systems are discussed below:
- System can be adjusted as per the requirement of the roofing project
- It can be made in all typed of colors, including white which has been known for energy conservation, lowering the urban heat island effect and improve the quality of air
- Difficult to puncture or break.
- Excellent resistant to fire
- Extreme temperatures, soiling or contamination does not impact its durability
- It shows flexibility and tolerance for low and high temperatures
TPO vs. Vinyl
It has been already mentioned that reinforced vinyl membranes have become popular soon after its introduction and has travelled worldwide in no time. Interestingly, the roofs that were installed nearly four decades ago in European countries and two decades ago in North America are still in good working conditions. Unfortunately, there were certain roofs of same materials installed towards the end of 1970s that did not work well. They were thin and not reinforced nor formulated membranes and had been installed in incompatible application of stone ballasts. TPO flat roofing systems installed in Europe withstood the milder climate of that place but succumbed to the extremes of northern US and Canada. Some instances were documented as failure of PVC. So the bottom line remains that a well-protected and well-formulated vinyl roof system is the most stable solution and has a high success rate in the industry. Even after 40 years spent in this dynamic market, it is still reigning the single ply market of Europe. The flexible polyolefin membranes, commonly known as FPO membranes came into being in 1991 in the European market and then, quite quickly in the same decade, moved on to United States where it was coined as thermoplastic polyolefin or TPO. However, TPO and FPO evolved to be quite different from each other in following respects:
- Thickness of an average FPO membrane in Europe is 0.064 inches while the most commonly used TPO in Canada has the thickness of 45 mils. In many cases, products with 45 mils label are actually equivalent 32 mil of polymer3
- Manufacturers in Europe make use of fiberglass for reinforcement along with polyester which improves the dimension stability
A TPO membrane that has been reinforced can expand and contract at least five times over a PVC membrane that has been reinforced.
Popularity of TPO is still soaring high in North America and Canada. Roofing companies in Toronto prefer TPO over EPDM and membranes that are dark in color. At Best Flat Roof, we only use top quality TPO membrane in order to ensure top performance and longevity. Beware of other less reputable contractors who may compromise in the quality of materials used and employ untrained or undertrained workers for the project. The result could be disastrous.
TPO and PVC can be similar looking but are completely different with even different performance levels. There are three features that make them similar, look, heat-weldable quality and their generic composition. This does not imply that their performance level would be same as well. When price becomes the deciding factor, the general public would go for the reasonable one without considering the durability of the final product. As per Single Ply Roofing Institute, TPO and PVC have outgrown all other commercial roofing membranes or the industrial single ply flat roofing market.
TPO Attachment Systems
TPO membrane can be either attached ballasted, mechanically or completely adhered.
When customer has neither money nor time, contractors may recommend ballasted system. Both membrane and insulation are laid loosely and membrane is secured at the edges only. Ballast should be water worn and even to touch. As well the ballast need to use a substrate to support the system load too.
Mechanically attached systems are capable of withstanding high wind though the cost incurred for installation is surprisingly low. There is a line of accessories which are used to fasten the attachments and keep them in place.
For undulating and odd contoured roofs, completely adhered system is the best bet. In such surfaces, mechanically attaching the membrane is not recommended. In Toronto, the roof also has to be stable in extreme wind conditions too.