Just like every other industry in the building industry, roofing materials have always been evolving to cater to the needs of homeowners. Flat roofing materials like TPO and EPDM have been gaining a lot of momentum in terms of sales and popularity since they have similar traits to PVC. Not only do these materials have the same installation process and characteristics, but it also offers a fair and competitive price.
While it’s a given fact that TPO and PVC can be installed over a single membrane for low-pitched and flat roofs and have seams that have been welded together, there are some distinguishable differences. These differences could be a deciding factor on whether you should purchase the material or not.
First, let’s discuss what are some of the key similarities and then filter out the differences. Right after, we will then discuss what are some of the differences in pricing.
Similarities And Differences
Even though each of these three materials might have some similarities, they do have some distinct differences. Knowing these differences will help us determine which one is the best well-rounded material for flat and low-pitched roofs.
TPO (Thermoplastic Olefin)
This type of material was designed to be an all-round step up from PVC. The key component of TPO is that it has a laminated nature. Often times, the material that’s used on the top layer is quite different from the material that’s used on the layer below. A wearing surface is at the top layer while the filler is located at the bottom of the material.
TPO is usually manufactured by having small rolls instead of one large sheet. In this case, it will require more seams than usual. EPDM, on the other hand, requires fewer seams because it usually comes as a large sheet.
This material also boasts relatively cheap and affordable prices. If you’re looking for the cheapest out of all the materials, then you should go for TPO. However, if you do compare it to PVC as an improvement, it does not live up to its name. As such, it’s best to do your own research first on the best manufacturers for this material and the warranties that come with it.
PVC (Poly Vinyl Chloride)
The first things that people think about when it comes to PVC are hard pipes and gutters. Well, yes, this is true. The PVC that you do see on rooftops is more pliable than their pipe cousins. Just like EPDM and any other materials, PVC membranes can be mechanically attached or even fully-adhered.
Even though PVC does boast some exceptional heat-resistance and punctures to leaks, it’s not going to adhere to other asphalt-based roofing materials. If you are planning on installing PVC together with asphalt-based materials, it’s best to make sure that they do not come in physical contact. In most cases, contractors will need to place separator sheets in between PVC and asphalt materials.
EPDM (Ethylene Propylene Diene Terpolymer)
This roofing material is one of the most widely used materials in the United States and worldwide due to its high durability and ability to resist different types of weather conditions. This material comes in both white and black varieties which makes it adaptable to warm and cold weather conditions. The white variety can easily deflect off UV rays that might cause your home to heat up. The black variety can help retain heat which can be effective in preventing ice dams from forming on your roof on colder seasons.
One advantage that EPDM has over TPO and PVC is that the average sheet can be a bit larger than the others. TPO will come in sheets of a 5 – 12 feet wide. This means that a sheet of EPDM can be easily mounted towards a 50 x 50 area. As a result, fewer seams are required than its TPO and PVC counterparts. On average, the thickness is around 45 – 60 mils.
There are different ways of installing EPDM and this is usually through a fully adhered surface, ballasted, and mechanically attached with the different seams being sealed with different liquid adhesives or specialized tape.
Which One Is The Most Cost-Effective?
It’s a given fact that the PVC membrane is generally more expensive than the other two materials for every square of the same thickness. However, the price of the materials will vary on the prices for each local builder’s depot that you go to. But if you do consider the prices of the materials, they are almost the same.
However, if you’re going to add labor costs into the mix, the total markup will be leaning towards TPO since contractors tend to have a higher markup for PVC for extra net profit. For both materials, the method of labor is generally the same but is more intensive towards TPO.
Ultimately, TPO does not have any advantages to pricing when compared to PVC. Again, not everything is set in stone or motion and prices could vary depending on the contractor that you’re contacting. It’s best to first negotiate prices first before making any final decisions.
In summary, TPO has been designed as a step up for both PVC and EPDM roofing materials. However, TPO has been facing several performance failures, recalls and updates. On the other hand, PVC has been in the market for 30 years but still has a good reputation for being a reliable material in the roofing industry.