Many building owners and manufacturers have asked me why I don't offer PVC membrane to my flat roof customers. I simply feel that PVC is too great of a risk to take.
What is PVC?
PVC, or Polyvinyl Chloride, is made from the polymerization of vinyl chloride monomer (VCM), a toxic, carcinogenic gas. It is a durable, economical material with many uses. 75% of all PVC consumption in North America is attributed to plastic pipes. PVC is also used as a membrane to cover flat roofs, and appears to the average person to look exactly like TPO membrane.
What are the risks associated with PVC?
Research shows that dioxin, which is the most potent carcinogen known to science, along with vinyl chloride and certain acids, are created and released during the production of PVC. These chemicals can cause severe health problems such as:
- neurological damage
- immune system damage
- respiratory problems
- liver and kidney failure
- birth defects
These are problems that the public and roofing contractors have a right to know about.
About 12 years ago, PVC was the primary material we used in our flat roofing division here at Brady Roofing. After we began installing PVC, I started to experience health problems. I have been healthy my entire life, so when these issues came on so suddenly, it made me wonder about the safety of PVC membrane. This led me to do some serious research on the material. I found that manufacturers actually know that PVC membrane is very toxic, but they were hiding these facts from me during our conversations.
My personal health problems included severe respiratory issues and neurological damage. The neurological issues are actually getting worse, despite the fact that I no longer install PVC. I don't want to go into my own health problems too deeply, but just to illustrate, my left lower body is experiencing a slow atrophy of the muscles due to neurological damage. My left calf is currently 1.25 inches smaller in circumference than my right. While I have no proof, I strongly believe it is caused from breathing the toxins found in PVC membrane. I have no genetic predisposition for such neurological issues.
Is this research relevant?
I approached our PVC manufacturer about the issue. They simply told me that there was no research to support my claims. In fact, there is a great deal of research done on the toxicity of PVC. The manufacturers can claim they are not relevant because these studies are done on the production of PVC rather than the installation risks. However, when you install PVC, you use hot air up to 1300 degrees F to melt the membrane and seal it. As the membrane melts, it can feel like you are breathing ammonia. The air can burn your sinuses, showing the presence of harmful chemicals being released, just as they are during production. Manufacturers will not provide this information to contractors and consumers.
Their argument is that the roofs are installed in open air, so there is enough ventilation to keep the installers safe. However, when you are welding, your face is 18 inches from the fumes. In a large majority of flat roofs there are also parapet walls, keeping the wind from blowing and clearing the fumes out. A significant percentage of the time, the fumes will enter your sinuses instead.
What can we do?
All of my research led me to believe that PVC is not a safe material to handle. This is why we have refused to install PVC membranes. Though there are variations of PVC membranes created in an effort to distance themselves from the hazards associated with PVC, careful examination will reveal that vinyl chloride monomers and dioxins are still present in these alternatives. While I have not drawn any strict correlations between PVC health risks and the customers, I have drawn risks to the installers, and I refuse to take any possible risk with our customers health as well.
We have chosen a new, innovative roofing alternative called TPO. TPO looks identical to PVC, but it comes without risks to the installer or customer. I believe that it is actually a better membrane because it does not get brittle like a dried up PVC pipe, as is characteristic of PVC sheets. TPO is flexible and highly energy efficient, along with being non-toxic. TPO is a younger product, it has only been around since since 1991. However, it is showing indications that it will last longer than PVC membrane.