If you’re reading this, you’re probably trying to decide on an energy-efficient flat roofing system. While there are several options you can look to for a flat roof solution, the most common ones used today are Polymerizing Vinyl Chloride (PVC) and Thermoplastic Polyolefin (TPO). PVC is the more traditional solution, but many enthusiasts have been advocating for the newer TPO as they believe that it is a better option. In fact, they have gone as far as billing TPO as the “newer, improved, version of PVC.” PVC has, however, proven itself in the durability and performance departments for almost 60 years.
Have a look at the information below, which compares PVC and TPO in terms of similarities and differences. The differences are the reason PVC roofing is the more highly recommended of the two.
What Qualities Do PVC and TPO Membranes Share?
Before jumping into the differences, first you need to understand the qualities that the two roofing solutions share.
- Color choices – While there are numerous colors available for thermoplastics, both roofing types are usually gray or white. These colors promote reflectivity and cooling, which is necessary as this material can soften if it continuously rises in temperature. Along with energy saving, the cool and reflective properties have received an Energy Star rating.
- Material – Thermoplastic is at the base of both membrane
- Welding technique – Both membranes make use of seam welding using heat.
- Multiple installation possibilities – Installation can be ballasted, attached mechanically, or adhered fully.
What Flat Roof Repair Differentiates PVC from TPO?
Now that the similarities have been covered, the next step is to have a look at the differences, which result in one being a more feasible option than the other.
Performance and Durability
This is the main area in which PVC roofing has its TPO counterpart beat. Based on how the two work, TPO roofing should theoretically last longer as a result of its chemical composition. The key point here is the lack of plasticizers in TPO membranes. The claim has been made that as time passes, plasticizers degrade and shift to the top layer. This means the membrane becomes susceptible to issues such as tearing. PVC uses these plasticizers, which is the reason for the existence of this theory.
This degradation, however, has not been the case, which is why PVC has garnered the reputation it has. In fact, there are PVC flat roof setups that have existed for over 30 years and are still standing today.
Note that PVC membranes abide by standards laid out by ASTM International and have been since the 1960s. An example of a big standard is the minimum breaking strength of a membrane, which is 200 lbs. PVC roofing surpasses this with an impressive 350 lb. minimum breaking strength. For this reason and others, PVC roofs can endure various weather conditions, water settling, and temperature changes without sacrificing structural integrity.
TPO roofing does not have this track record because it is technically still being perfected. In fact, TPO roofing has gone through multiple revisions and each requires new data to substantiate its effectiveness.
ASTM standards for TPO roofing are relatively new as well, which is why previous builds were known to degrade quickly when exposed to high thermal conditions for long periods.
PVC roofs are built to ensure that fires are not a huge problem. The materials used are not combustible, they are difficult to light, and they also have self-extinguishing properties that are triggered once the source of fire is taken from the equation.
Note that the idea is not to convey that TPO builds are inferior, however it is not perfected and going cheap may cost you more in the long run than just choosing the more tried and tested flat roof solution.
PVC and TPO have different chemical compositions, which is possibly the most notable difference between the two. This chemical composition translates to where each roof type shines.
TPO membranes are comprised of a mixture of ethylene propylene polymers and polypropylene. This combination is refined using polyester. This combination is intended to result in the following:
- Resistance to weather changes and numerous conditions
- UV absorbers to provide immunity against UV rays such as those from the sun using absorption
This combination is intended to both stand up to the elements and to promote the flexibility of TPO.
PVC membranes on the other hand are made up of a chlorine and ethylene blend. Sheets of PVC are made up of the following:
- UV inhibitors to provide immunity against UV rays such as those from the sun by blocking them
- Plasticizers to allow PVC sheets to be durable while being flexible
- Biocides to mitigate and prevent growth and development of things such as fungi, algae and mold
- Polyester reinforcement for longevity and strength
- Flame retardants for prevention of ignition and self-extinguishing
The focus of the composition of PVC is to ensure that the material remains flexible and provides durability to roofs.
These days, making considerations for the environment is a high priority. This is especially true as climate change and degradation of resources is proof that a conscious effort needs to be made to save the planet.
The product as the base of TPO membranes is Polyolefins, which is not necessarily a reusable material after use. Disposing of same is also not always an option should you ever have to remove the sheets from your roof.
PVC roofs on the other hand most often use vinyl as the base material. While the solar reflectivity (as opposed to absorption) that was discussed above is a great perk, vinyl is also a great choice for those who care for the environment. Vinyl is one of the few materials used in building that is completely recyclable. This applies even after the vinyl has been in use for years.
Which is a Better Option?
You can probably infer this based on the information above, but the recommended choice for your flat roofing is PVC. TPO may make the claim to be the better choice but considering the kinks are technically still being worked out and the fact that it is still establishing its reputation, it may be a much better idea for you to go with the more established PVC, and you can do so with no doubt that your building is protected by the best in the industry.
With over 40 years of experience in providing reliable roofing services, Commercial Flat Roofs is your premier service provider for commercial roofing, industrial roofing, flat roof installation, and flat roof repair. As you read above, PVC roofing has numerous advantages over its TPO counterpart and for this reason, Commercial Flat Roofs only offers the superior PVC roofing. We provide service for flat roof all over Ontario. Flat roofs in Toronto are eligible to receive grant money from the City of Toronto when using our PVC Roofing Systems as a solution for your flat roof repair or replacement.
Commercial Flat Roofs offers two main services:
- Flat roofing – Done using high quality Duro-Last rooftops for maximum UV resistance, reflectivity, and flexibility. Best of all, you can enjoy a superb warranty that does not exclude ponding water. We offer all flat roof repair for all of Ontario as well as doing flat roof Toronto areas.
- Prefabrication – Take advantage of our prefabricated components (also from Duro-Last) that go a long way in labor cost reduction and leak elimination.
Contact us today to discuss your options, get a free inspection and quote. You shouldn’t have to worry about the integrity or performance of your roof. We care for all of our clients and offer flat roof repair, flat roof replacement, industrial roofing and commercial roofing services. Roofing services are offered in all of Ontario, Canada.