Thermoplastic for Commercial Roofs
When it comes to commercial roofing, it is essential to find the best roofing materials that are durable, energy efficient and economical. Thermoplastic is one of the best solutions for commercial roofs available today. Thermoplastic roofing membranes do not have chemical cross linking. Thermoplastic membranes can be softened or hardened repeatedly by heat changes without damage. The roof membrane is often seamed using heat welding or solvent welding.
History of thermoplastics
Thermoplastics are some of the materials used in flat roofing systems for commercial roofs. Others include modified bitumen, EPDM and BUR. Thermoplastics have been in use for various applications since the 80s. However, it was not until 1989 when thermoplastics were introduced to the roofing industry as non-reinforced sheets and in 1993, the non-reinforced material was replaced by a new membrane that had reinforcing fabric. Since then, the popularity of thermoplastic in commercial roofing application has greatly in increased and thermoplastics have become a staple in the roofing industry.
Types of thermoplastic roof membranes
There are about four common types of thermoplastic roof membranes in the market today;
- Polyvinyl chloride (PVC)
- Compounded thermoplastics
- Thermoplastic Olefin (TPO)
- Chlorinated polyethylene (CPE)
Polyvinyl chloride (PVC) and Thermoplastic Olefin (TPO) are the most common thermoplastic roofing membranes used in commercial roofs.
Polyvinyl chloride (PVC)
This roofing membrane is manufactured by spread coating or calendaring. Polyvinyl chloride (PVC) is reinforced using polyester or glass-fiber mats. The sheets contain stabilizers, plasticizers and other additives that improve its flexibility and the best physical properties. You can even find Polyvinyl chloride (PVC) membranes with nonwoven fleece backing. Polyvinyl chloride (PVC) is available in a variety of colors although the most common are gray and white. They are usually 45-90 mils thick and can be as much as 12 feet wide.
Thermoplastic Olefin (TPO)
Thermoplastic Olefin (TPO) is made of a blend of ethylene-propylene and polypropylene polymers. Other substances such as colorants, UV absorbers and flame retardants are also added to the TPO to give it its desirable qualities. Thermoplastic Olefin (TPO) are slightly thicker than PVC membranes going up to 100mils thick but still come in standard sheets that are 12 feet wide or smaller. Most TPO membranes are usually white in color.
Comparing Thermoplastic and Thermoset
Thermoset roofing membranes are quite common and come as a single ply rubber membrane that has a thickness of about 45-60 mils. It is often made from synthetic rubber and thermoset is not a continuous membrane. Both thermoset and thermoplastic are used as commercial roofing materials. However, thermoplastic membranes are more suitable for industrial purposes because they have more resistance to chemical and water damage as compared to thermoset roofing membranes.
Thermoplastic membranes are also easier to coat on the commercial roofing due to the production size. They require fewer seams as compared to thermoset membranes which are non continuous. Although both membranes have great resistance capacity, it is advisable to use thermoplastic roofing in production and manufacturing commercial buildings due to its desirable physical qualities.