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Property and business owners in Dallas, TX, have a long list of responsibilities. Monitoring roofs on commercial or industrial buildings should be close to the top of that list. The integrity of an entire structure, and its contents, depend on a high-quality roof in good condition. Roof repair or replacement may inspire thoughts of time-consuming installation and heavy, unwieldy materials, but there are other options. A single-ply roofing membrane is a lightweight, waterproof layer of material that rests on a building’s surface.
Although they may seem flimsy, single-ply roofing membranes are quite strong and durable. Thin, flexible single-ply membranes are easily handled and protect structures from the elements, such as rain, snow, and UV rays. Most single-ply roofs have four parts, including an insulating layer, the membrane itself, and protective flashing along edges to control excess water.
The fourth component can be a set of fasteners, adhesive, or welding seams to bind layers together. Membranes can be mechanically fastened to insulation, ballasted with rocks, or fully adhered to a solid underlying surface. The most common types of single-ply membrane roofs are PVC, TPO, and EPDM.
Polyvinyl Chloride (PVC)
Polyvinyl chloride, commonly known as PVC, first appeared nearly 60 years ago, and it remains popular in commercial roofing to this day. PVC is manufactured from salt combined with natural gas or oil to create a white compound. The compound is called vinyl chloride monomer.
Manufacturers may use one of many chemical processes at this stage to turn vinyl chloride monomer into flexible or rigid PVC with various properties. Chemical treatments enhance strength and durability. A finished PVC sheet may contain plasticizers, ultraviolet light inhibitors, polyester or fiberglass, or biocides to inhibit bacteria and mold.
A scrim between membrane film layers provides stability and puncture resistance. The scrim contains another layer of material, known as a weft insertion, that prevents further rips or tears if the membrane ever does sustain damage.
Roofs with PVC membranes have an average breaking strength of 350 pounds per square inch, which is significantly stronger than the industry minimum standard of 200 pounds per square inch. PVC surfaces are also highly resistant to corrosive chemicals.
As a flexible plastic, PVC tolerates thermal expansion and contraction in response to temperature changes. It can be installed as commercial roofing at any time of year, regardless of ambient temperatures. A reflective surface minimizes UV ray exposure and improves a structure’s energy efficiency during hot summer months. PVC membranes have Energy Star and Cool Roof ratings.
Lightweight PVC commercial roofing membranes are frequently installed over the surface of an existing roof, although this is only feasible for roofs in good repair. Installation is relatively fast and easy when the underlying roof remains in place.
Heat welding membrane seams also contribute to the durability and longevity of PVC commercial roofing. The flashing details and sheets of each membrane component melt together and form a continuous membrane sheet. Many PVC membranes are prefabricated. Manufacturers perform any necessary welding with appropriate tools on the factory floor before shipping.
Thermoplastic Polyolefin (TPO)
Thermoplastic polyolefin, or TPO, is another type of roofing membrane. It was developed in Europe with the intention of combining the best qualities of PVC and EPDM membranes. Consumers in the US began using TPO in the early 1990s.
Industrial fabric mesh scrim-reinforced TPO layers and improves resistance to tears, punctures, and impact damage. Some TPO membranes are treated to inhibit mold growth. You may even see lower energy bills after installing a new TPO roof because the membrane reflects heat instead of conducting it onto the building surface.
TPO membranes are known for being very lightweight and easy to install. One square foot of TOP with a 60-mil thickness weighs only 4/10 of a pound. Overlay installation, which is simply positioning the TPO membrane over the current roof, may be possible. Consult your local roofer to find out if local commercial roofing codes permit overlays.
TPO membranes may have glued or heat-welded seams, but cold temperatures may prevent effective heat welding. A TPO roof withstands ice and snow after the membrane is in place, but property owners should avoid installing TPO during cold winter months.
Consult a commercial roofing professional in Dallas, TX, if you’re interested in a TPO membrane. TPO is made with a wide range of formulations between various manufacturers. A professional can help you find the most appropriate TPO material for your structure. Identifying TPO formulas is important for patching, repairing, or reinforcing an existing TPO membrane as well. The new membrane must be compatible with the existing membrane for effective repairs.
TPO membranes are susceptible to chemical damage and absorb grease and oils, which leads to deterioration and weakness. Restaurants and other businesses that regularly work with grease, oils, and other fats may want to consider PVC membranes instead of TPO for their commercial roofing needs.
EPDM, or ethylene propylene diene monomer, is a type of synthetic rubber single-ply membrane roof with thickness options between 30 to 100-mils. It’s often used for flat or low-slope commercial roofing projects due to its long-term flexibility and ability to withstand strong winds, rain, snow, and high temperatures. Many property owners also appreciate the wide range of available colors.
An EPDM roof can last up to 30 years if it’s installed correctly. The synthetic rubber material is waterproof and nearly impervious to ozone and UV ray damage. EPDM doesn’t contain any organic material, so mold and bacteria find the environment unfavorable and decay is not a concern.
Call the professionals at Longhorn Commercial Roofing with any commercial roofing questions. The professional roofers at Longhorn can evaluate your existing roof and help you choose an appropriate replacement material or a new roofing system.