In this article we’re going to dive down into nine quick fire facts about PVC roofing, so all your questions are answered.
Polyvinyl chloride, or PVC, is a durable plastic that makes an excellent roofing material. This strong, versatile plastic offers protection against rain, snow, UV rays, fire and water, and won’t discolor in the sun.
With that said, let’s consider in more detail what PVC roofing is, how much it costs and how to install it – plus many other questions about this robust material.
What is PVC Roofing?
PVC (or polyvinyl chloride, to use its full name) is a robust plastic that makes an excellent roofing material. The strong, stable plastic offers protection against UV, fire and water, and won’t discolor in the sun.
The single-ply roof is often used on commercial buildings with flat or slightly sloping roofs. Its seams are usually welded, which allows for any expansion and contraction, as well as being impressively water-tight. It even survives water pooling on it during heavy rainfall.
It’s also a popular choice because it’s easy to install. The lightweight plastic can be manufactured off-site and then simply attached over the existing structure. PVC is used in industrial buildings because it is chemical and heat resistant, and can survive in many harsh environments.
What about its green credentials? PVC has Energy Star and Cool Roof ratings, and is made using less oil and petroleum than similar tough plastics. It helps to hold the building at the right temperature, reflects the sun, and can be recycled after its long life.
In our yards, it’s most commonly found in corrugated form, used in garden buildings such as sheds and porches. It can also be used for extension roofs for conservatories and sun rooms. It’s a good domestic choice for the same reasons that it’s a preferred material for commercial buildings.
How Long Do PVC Roof Panels Last?
All being well, a PVC roof should last for 20 to 30 years. There are several reasons for its long life. PVC is an incredibly tough plastic that resists heat and chemicals, and won’t pick up so much as a mold spot in wet conditions.
PVC is an astonishingly strong material. For example, the American Society of Testing and Materials (ASTM) specifies that a roofing membrane must have a weight capacity of 200 lbs per square inch. PVC can hold a weight of 350 lbs.
It’s also easier to repair than some other plastic roof materials. Those welded seams are far more durable than taped or glued seams, so will last longer and need less maintenance.
How Much Does PVC Roofing Cost?
Looking at a few suppliers, it seems that the general cost range for PVC roofing is between $4 and $12 per square foot, which is quite a large margin. Several sources mention $7.50 per square foot as a reasonable starting price.
As we’ve already mentioned, PVC is super-tough, lasts for up to 30 years, and won’t fade or go moldy. It may be a case of taking a deep breath and going for this more expensive roofing material, as you know that it will last.
What is Better TPO or PVC?
A TPO (Thermoplastic Polyolefin) roofing membrane is made from ethylene propylene rubber. It is fairly similar to PVC in many ways, but can be a bit cheaper. It’s flexible, so is unlikely to tear as it allows for any building movement. Its seams are welded like PVC, and it’s extremely good at regulating temperature.
It’s also green, and like PVC, can be recycled. TPO is Cool Roof and Energy Star rated, making it a great choice for both energy saving and liveable comfort. It’s made without using any harmful chlorine
So far so good. So what is the main downside of TPO? Well, it’s the new roof on the block, and we simply don’t know its longevity yet. We’ll all happily pay more for PVC because we know that it’s going to last. It’s easier to face the upfront cost when you know the roof’s still going to be fine in 20 years’ time.
Manufacturers are still changing the formulation for TPO, trying to find which works the best in terms of longevity versus cost value. This means that not all TPO roofs perform in the same way. The American Society of Testing and Materials (ASTM) also keeps revising the standards for TPO to reflect this; something else to bear in mind.
If you don’t want to take the risk, PVC is a known quantity, and is proven to be durable and reliable. However, it can’t be installed near any asphalt-based product. If this is the case with your project, either go to the hassle of installing a separator sheet, or simply try using TPO instead.
How Do You Install PVC Corrugated Roofing Sheets?
Obviously, there are all sorts of PVC roofs, from massive commercial factories to small yard sheds.
The simple short video below from New Zealand experts Mitre 10, shows you the basics of installing a small corrugated roof above your porch. You really need to watch the installation clip to see how it’s done, but we’ve summed up the main stages here:
- Measure the roof area, allowing for an overhang.
- Mark these measurements on your first PVC sheet.
- Cut the sheet to size (see below for how to cut PVC roof panels).
- Mitre 10 installs an apron flashing against the weatherboard of the house wall, to ensure a weather-tight seal. Do this by prising between the boards with a bar to create a gap, then tucking in the apron. The rough edge of the PVC panels tucks underneath this, and you can secure this as you go along.
- Screw the first PVC sheet to the roof beams, attaching it every third corrugation.
- Repeat for every PVC panel. Overlap the panels by just one corrugation. As you go along, keep re-nailing the weatherboard into place.
Because this clip wasn’t filmed in the States, you can ignore the advice about planning rules. However, it’s still always a good idea to check with your local authorities before embarking on any building project in your yard, just to be sure.
How Do You Cut PVC Roof Panels?
It’s straightforward to cut corrugated PVC roof panels to the right size. You need a circular saw and a carbide blade, and a way of securing the panel as you saw (you don’t want to wobble off your cutting line). Wear safety goggles.
- Place the piece of PVC roofing on a flat surface, then measure and mark where you want to cut.
- Place the PVC over the edge of the flat surface (the marked line should be around an inch from the edge). If there’s a lot hanging over, ask a second person to support it (and give them a pair of safety goggles, too).
- Set the circular saw blade to full cutting depth. Hold the blade guard open with one hand, and saw along the marked line.
- When the saw has gone far enough for the guard to rest on top of the sheet, you can release the guard. Press the sheet down against the flat surface while you saw, to minimize vibrations.
- Continue cutting to the edge, and let the excess fall away (mind out for that second person…).
Can You Paint PVC Roofing Sheets?
Yes, you can paint PVC roofing sheets, but it involves preparation and specific paints. You’ll need to use a paint that’s formulated for plastics, like Krylon Fusion or Rust-Oleum Plastic. For small areas, spray paint gives a smooth finish.
Make sure the PVC is well cleaned before painting – if you’re painting a smaller roof, you can even wipe it down with acetone to make sure it’s extra-clean. When it’s 100% dry, apply a coat of white PVC primer. You may need up to three complete coats of paint to cover the PVC.
What’s The Difference Between Polycarbonate & PVC?
Polycarbonate is a tough thermo plastic that’s often used for roofing. It’s insulating and UV resistant, and is a popular roofing material. It’s lightweight, easy to cut, and straightforward to install, making it a popular choice among builders and DIY enthusiasts alike. Clear polycarbonate is used as an alternative to glass for conservatory and greenhouse roofs.
Polycarbonate is even stronger than PVC (apparently it’s almost impossible to break it, but we don’t want to tempt fate…). This means, of course, that it costs more. PVC has another advantage: polycarbonate can scratch, whereas PVC rarely does.
Where Can I Buy PVC Roofing Panels?
It’s easy to get hold of PVC roofing panels, and you can usually pick them up from Home Depot and Lowe’s. You can even buy sheets on Amazon. Your local roofing or builders’ suppliers will also be able to provide them.
Of course, you may decide to have your roof installed by a professional (it’s simple enough to install a greenhouse roof, less so a conservatory one). In which case, they will be able to supply the panels for you.
Strong, long lasting, cheap-to-buy and versatile – PVC is a great roofing solution for all your home and backyard roofing projects.
It protects against all the elements, including UV sun rays, rain, snow and wind – and will literally last a lifetime.
You can also install it yourself relatively easily, and with guttering and down pipes all round it can look really smart.
So the last question should really be: ‘What’s not to like about PVC?!”.