One of the most important choices you can make when you're getting a new roof is the type of material you want. PVC is a common, waterproof material used for low-sloped roofs that lasts quite a long time. After its 40 years of use in construction, some myths have sprung up about it, including being unsafe to walk on. We've done the research about whether or not it is safe for both the PVC roof and the person walking across it.
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PVC roofing is relatively safe to walk on. It's a common myth that walking across PVC roofing will cause spiderweb cracking in it, but it is absolutely strong enough to hold up a person's weight, as long as the decking underneath is also strong enough. You're much more likely to damage the roof by puncturing it with a tool than by walking on it. On the other hand, you will generally want to avoid walking on PVC roofing, as it is incredibly slick when cold or wet, which makes it much more likely you will slip and fall.
PVC is strong enough to support your weight without damage but poses a slippery risk to walk on. Now that you know a little about PVC roofing, you may have other questions. We encourage you to continue reading to learn about how PVC roofing is installed, how long it lasts, and other common questions regarding PVC roofing.
Safety of PVC Roofing
PVC materials have been used in construction for over forty years. Their formulas have been tested and improved on during that time, resulting in incredibly strong material. As a safety concern for the roof, PVC is perfectly fine to walk on. The material should suffer no damage from a person walking across it. The only thing to watch out for is dropping tools or other sharp objects onto it, as they can puncture the material.
While PVC is strong enough to hold a person's weight, it isn't entirely safe for the person walking across it. PVC is a slick material, and this is worse when it gets cold or wet. Walking on PVC comes with a high chance for a person to slip and fall, and on a sloped roof, this could lead to bad injuries. The best option if you must walk on PVC roofing is to wear gripping shoes, do not shuffle your feet, move slowly, and pay attention to your balance to avoid falls.
How Is PVC Roofing Installed?
For most people, PVC roof installation is not a DIY project. This is because heat welding is required to bond the seams together and is better left to qualified roofers. Keep in mind that the majority of problems that arise later in PVC roofing are due to poor installation, not the material, so the installation is the most important step.
The installation process is fairly straightforward and can be summed up in just a few steps.
- Prepare the decking.
- Lay the material.
- Weld the seams.
- Attach the flashings.
Types of Installation
There are generally three ways PVC roofing is installed. The types of installation for PVC roofing include: fully adhered, mechanical, and ballasted
Fully adhered installation essentially means gluing down the PVC sections with an adhesive. This type will only work when the region's average temperature is above 40 degrees Fahrenheit since the adhesive would otherwise freeze. Fully adhered installation is recommended for impermeable roofs, like concrete. The main issue with this type is that it can form condensation underneath the material, loosening it from the roof. Even if the material is bonded properly, it still needs mechanical parts around the roof's perimeter.
Mechanical installation means the roof is held together by parts. Heavy plates and screws hold the material to the roof, making it a perfect choice for high wind areas. Flat roofs put together this way are virtually hurricane-proof.
Ballasted installation means the material is held down by weight. This means no bolts or screws and no adhesive. Generally, the PVC will be laid loosely on a roof, and something heavy will be poured over it, like a layer of rocks. The weight is what holds the material in place.
While it has already been stated that PVC installation is not a DIY project, you can do it if you happen to have heat-welding experience. Again it is still better to allow a professional to install PVC roofing. That being said, to see PVC roofing being installed in steps, check out this YouTube video.
How Can You Tell The Difference Between TPO And PVC Roofing?
PVC and TPO roofing are used for similar purposes on low-sloped roofs. The difference between the two is in their actual makeup. TPO roofing is made of an ethylene or polyethylene thermoplastic bound to ethylene propylene rubber. PVC is made by polymerizing vinyl chloride monomers, then adding plasticizers for more flexibility. But you're probably wondering what that actually means. We'll break down a few differences in their properties in the following lists.
- Better energy efficiency.
- More difficult to install due to stiffness.
- Newer, with more manufacturers using lower quality formulas.
- Lower cost per square foot.
- Better resistance to weathering and punctures.
- More resistant to chemicals.
- Incredibly durable.
- Easier installation.
How to Tell
The easiest way to tell the difference between the two is to check the material labels on the shelf. Just looking at the two materials, it's unlikely you can tell the difference. Visually, there is no difference between the two once applied. The only way to tell is to touch the material as PVC will have a more waxy and pliable feel than TPO, and PVC has a distinct smell telling it apart. Unless you're well-versed with the materials, however, you probably still won't know the difference.
How Long Does A PVC Roof Last?
PVC has been used in construction for well over 40 years now. Over that time, it has been studied and tested for the best formulas and binding materials. A properly installed PVC roof should last 25 years or more. Make sure to use a quality contractor, as the installation is more important than the materials for the longevity of a PVC roof.
For the most part, all PVC brands have the same longevity. While it has been said in this post, installing a PVC roof is the most critical factor when it comes to how long the roof will last. Make sure to use an experienced and qualified contractor to get the longest possible life out of your PVC roof.
If you're interested in how long wood roofs last, check out our article "How Long Does A Wood Roof Last?"
How Much Does PVC Roofing Cost?
On average, PVC roofing should cost between $4 and $7, including labor costs. It isn't uncommon for it to cost between $8 and $12 as well. For an average-sized roof of around 1500 square feet, the roof's total cost could be anywhere from $6,000 to $18,000. If old portions of a roof need to be removed, expect to pay a dollar or two per square foot for the removal on top of that cost.
The most significant factor in the cost of a PVC roof is the size of the roof in square feet, but it is not the only factor. Different colors and patterns can also vary in price. White is the most common choice, as it is reflective and helps with energy efficiency in the building. PVC roofing also comes in black, grey, tan, and other colors. Some varieties are patterned and look like shingles from a distance.
Can You Walk On PVC Roofing?
You can walk on PVC roofing. It is incredibly rare for someone to damage PVC roofing by walking on it, and the real risks come when the roofing is wet or cold, making it slippery and easy to fall. While it may not damage the PVC, it's better to avoid walking on it when it is at its slickest to prevent possible injuries from falling.
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