PVC and TPO roofing materials are both good options for a flat or low slop roof, but of course you want to know what the the differences are between the two and which roofing option, PVC or TPO, is better for your roofing project. That’s what we’re going to get into today, so lets take a look at what each of these roofing types are, followed by a side by side comparison in areas such as cost, installation, lifespan and eco/climate considerations.
Please let us know your opinions and experience with either PVC or TPO roofing in the comments section below. And when you’re finished here you might like to know the differences between TPO roofing Vs EPDM roofing.
WHAT IS PVC ROOFING?
PVC stands for polyvinyl chloride. Using PVC for commercial buildings and low-slope residential roofs has become a more popular option than TPO and EPDM. PVC roofing is a single membrane that has two layers of PVC with a reinforcement scrim between the layers. The top layer can be any color, but white is most common because it is the most resistant to UV and heat. The bottom layer of PVC is black and is more flexible than the top layer. The seams on PVC roofs are heat welded and extremely waterproof.
WHAT IS TPO ROOFING?
Thermoplastic polyolefin or TPO is a single ply membrane that is an affordable choice to use on flat or low sloping commercial or residential roofs. TPO roofing material consists of a thermoplastic polyolefin layer covered with scrim fabric, such as fiberglass or polyester and topped with another layer of TPO. The material is available in thicknesses from 45 mil to 90 mil. Using thicker material is more expensive but produces a more durable roof.
Installing PVC and TPO roofing should be done by a licensed contractor because it requires a significant level of expertise gained through experience. There are a number of different ways to install these materials, but each method of installation begins with some type of insulation board covering the roof deck. Then the TPO or PVC material is laid on top. Roofing installation options are:
- Fully adhered using glue
- Mechanically attached with screws
- Held in place with termination bars – Roof edges are wrapped, and the bars are fixed to the fascia
- Ballasted with stone to hold the material in place
Installation time on most residential jobs is 3-5 days to remove old roofing, if necessary, prep the roof deck and install the insulation board and TPO or PVC.
Both TPO and PVC roofing are cost-effective roofing options. PVC roofing starts at about $4 per square foot and ranges up to $12 per square foot, though most jobs cost less than $10/sq. ft. This includes all the material and labor costs for the project. Cost factors are the thickness of the PVC used plus installation factors. TPO roofing is comparably priced anywhere from $6.50 per square foot to $12 square feet when professionally installed.
As mentioned above you’ll want to find yourself a reliable and experienced contractor to carry out the work so please consider getting several quotes from local roofing specialists in your area.
PVC generally has a 20-year warranty. When the seams are heat sealed correctly and the entire roof is properly maintained, PVC roofs have been known to last 30+ years. TPO roofing warranties range from 10-25 years. It’s a newer roofing material, so the verdict on durability isn’t in yet. Plus, TPO formulations have changed over the years and continue to evolve. No brands use the exact-same formulation. Current best estimates are that a TPO roof will last 18-25 years.
Both TPO and PVC can be considered “green.” PVC roofing is the only single-ply roofing material that can be 100% recycled. White in color, it has excellent solar reflectance, keeping the roof cooler and lowering air conditioning costs. However, an environmental negative for PVC roofing is that it contains chlorine, a toxic chemical and harmful to the ozone layer. Chlorine is emitted during manufacturing and will be released if the PVC burns. PV
TPO roofing is usually white or tan in color, so it also reflects heat and cuts cooling costs by 30% compared to asphalt roofing. Also, TPO roofing can also be manufactured with recycled materials.
The major issue or concern with PVC roofing is that in areas with extremely cold temperatures the material can become brittle and crack due to the cold and freeze/thaw cycles. It is a better choice in moderate-to-warm climates where it is less prone to weather damage and where its energy-saving properties are appreciated.
TPO is a versatile roofing material suitable to most climates. However, extreme and prolonged heat has been known to cause thermal expansion of the material, contracting as it cools. This process can cause small cracks in the roofing material that result in leaks.
PVC has been around for a long time with a track record for durability and strength. And it can be recycled. Where both PVC and TPO are suitable materials for your climate and roofing project, it makes sense to go with PVC. But do your research when hiring a roofing contractor, whatever material you choose. Plan to pay a little extra if necessary to ensure the contractor you select has the experience required for installation that will hold up in the decades to come.