Single-ply membrane roofs are rubber or other synthetic sheets that are ballasted or chemically bonded to insulation to produce a layer of protection for your building. These roofs are often used on flat or almost flat roofs, such as those found on commercial buildings.
Synthetic sheets can be classified into three popular categories: EPDM, TPO, and PVC.
Each of these materials has its own set of benefits and drawbacks. To help you make an informed decision, we will go over the characteristics of each material as well as the flaws that you should be aware of.
EPDM
EPDM (ethylene propylene diene monomer) is a synthetic rubber material with high tensile strength, durability, flexibility, and tolerance to varied weather conditions. As a result, EPDM roofs can survive for decades with little maintenance since they are resistant to day-to-day and seasonal temperature variations. When subjected to hot or cold conditions, the material does not easily change its shape, thanks to its thermoset properties.
EPDM comes in huge sheets or rolls, making it simple to install. One of the benefits of EPDM roofing is the lower cost of installation. EPDM is one of the most cost-effective roofing materials on the market, costing around $0.80 per square foot. Because the EPDM roofing membrane is so light, the roof deck will not need to be reinforced.
In fact, removing everything from the roof, applying an adhesive, and then rolling out the membrane is one of the most effective ways to install EPDM. Because there are few seams, leaks are uncommon (as long as the installation follows the manufacturer's instructions), and a high-quality EPDM can last 20 years or longer.
Pros
- Most cost-effective material for flat or low-sloped roofs
- Long-lasting roofing material with a lifespan of more than 20 years
- Energy-efficient as it can be easily combined with polyiso insulation
- Requires fewer seams owing to its large sheet size
CONs
- Slightly more expensive when mechanically installed
- Requires rigorous maintenance
- Not resistant to animal and vegetable oils
Pro Tip: EPDM is usually black in color. But manufacturers are now selling white-on-black options. These are essentially EPDM sheets with titanium oxide lamination. Although the new alternative is more expensive, the lamination makes the surface less stable. If you're convinced EPDM is the way to go, you would rather choose black over white.
TPO
Thermoplastic Polyolefin, or TPO, is the fastest-growing commercial roofing material on the market. It is a form of rubber that is resulting from a combination of polypropylene and ethylene-propylene rubber.
TPO has the advantage of being the cheapest material for single-ply membrane roofs, as it is less expensive than EPDM and other varieties of rolled rubber roofing. The color is the next benefit to mention. TPO is usually white on top, which helps reflect the sun's light and prevents heat buildup within the structure.
Another advantage of TPO is that it allows for multiple installation options. It can be adhered to the roof deck with adhesives or nailed straight to it. It's also possible to heat weld it around chimneys and other protrusions.
Most importantly, TPO is incredibly durable. This material is not only resistant to corrosion but also doesn't encourage the formation of mildew or algae. Moreover, it is incredibly easy to clean, as it doesn't need to be pressure washed.
Pros
- Resistance to ozone, UV radiation, and some chemical degradation at a low cost
- Reflects heat better than EPDM
- Resistant to mold development, dirt buildup, tears, impacts, and punctures
CONs
- Heat welding the seams requires high-quality installation to withstand the test of time
- It is not as durable as EPDM
- Can pull away from seams and curbs after shrinking
- Could deteriorate when exposed to reflected sunlight and high heat
- Requires highly experienced roof installers
Pro Tip: If cheap is what you're looking for, TPO is the least expensive option of the three. However, it is less likely to hold up for long, comparatively. But all TPO roofs are not created equal; some will last longer than others. It, therefore, pays to buy from a reputable manufacturer. Also, be on the lookout for favorable warranties.
PVC
PVC membranes are unrivaled in terms of durability. Polyvinyl Chloride, or PVC, is a tough plastic substance that can bear a lot of strain, whether from heavy use or natural forces. That is why it is one of the most widely used roofing materials.
Prefabrication is another benefit of PVC roofing membranes. The roof can be measured and built off-site by the contractor. As a result, the roof's seams are stronger, and the fit is more accurate.
The only disadvantage of PVC roofing is its cost. However, while it costs more than TPO or EPDM, your roof will not only survive longer, but will also be backed by a lifetime warranty.
Furthermore, while prefabrication has a greater material cost, it takes less time to install. This translates to decreased labor costs and fewer business interruptions.
Pros
- Durable roofs that can last 20 years or more
- Chemical resistant
- Fire resistant
- Hot-air welded seams for stronger bonds
- More eco-friendly
CONs
- More expensive per square foot than EPDM and TPO
- Won't adhere to asphalt materials
Pro Tip: PVC is arguably the best of the three roofing materials as far as durability is concerned. Although it may cost you more, it is the most reliable option in the long run. Moreover, it is the perfect choice for warehouses or manufacturing facilities, where there are substantial amounts of chemicals and a high risk of fires.
EPDM vs TPO
EPDM has been around longer. But TPO is gradually gaining popularity and may be the most preferred option in the future. Both systems are viable options, but they differ in several ways.
For starters, EPDM comes in black while TPO is white. Naturally, bright colors will reflect sunlight while darker ones will absorb it. As a result, EPDM roofing forces air conditioners to work overtime during the summer.
On matters size, EPDM sheets are larger compared to TPO. While TPO sheets come in rolls of about 12 feet, an EPDM sheet can measure 50 feet by 50 feet. The advantage of large sheets is fewer seams resulting in more stability and fewer leaks.
Rubber Membrane vs PVC
EPDM and TPO roofs are made from synthetic rubber. On the other hand, PVC is a polymer made by combining ethylene, hydrochloric acid, and oxygen gas in an industrial process.
Rubber membrane and PVC roofs also differ when it comes to seams.
PVC is joined at the seams through hot-air welding. The process results in a monolithic structure that is durable. Rubber membranes are often joined at the seams with glue or tape. The result is a structure that is more likely to tear with repeated expansion and contraction.
TPO vs EPDM vs PVC
So which material is ideal for your home or business?
Choosing the best roof for your commercial project demands careful consideration and decision-making. Think about factors such as the typical weather conditions to which your property is frequently exposed, the architectural style of the structure, and even what your business does or produces.
Contractors can choose how they want to install these materials. In addition to utilizing adhesives to secure them to the roof, fasteners can be utilized to secure them in hard-to-reach regions. They can also be ballasted with stone to help them look better.
Single-ply membrane systems are suitable for a wide range of business and building types, but to get the most out of your roof, you should consult with a professional commercial roofer.
The following table sums this up.
Roof Type | EPDM | TPO | PVC |
|---|---|---|---|
Suitable For | Those looking for a middle ground between PVC and TPO | Those on a budget | Those looking for the most durable single-ply membrane roofing |
Don't forget; there are other numerous solutions available such as KEE and PDM roofs which you might also want to consider.
FAQs
The following are some of the most frequently asked questions about these three roofing materials:
Q: Are PVC Roofs Made of Hazardous Materials?
A: The biggest controversy surrounding PVC is because it contains chlorine. Sure, chlorine can be a particularly deadly gas in its elemental state. However, this gas is found naturally as a compound in rocks and large quantities of water. In fact, it is required as a nutrient by humans, animals, and plants.
The pale green gas is removed from salt during the manufacturing of vinyl and then chemically sealed into the product. As a result, even if the PVC roof catches fire, this chemical procedure assures that no chlorine is released into the atmosphere.
Q: How Strong are TPO Roofing Systems?
A: Seams on TPO membranes are welded with hot air. These seams are three times stronger than tape-based seams on traditional rubber roofs. It's also six times stronger than glued-seam roofing. TPO roofs have unrivaled weather resilience because of their improved strength, making them the perfect solution for larger roofs that would typically require numerous layers of tape or adhesive to fix the membrane roof.
Q: Is EPDM Suitable For Retrofitting an Old Metal Panel Roof?
A: Yes. Insulation is used to fill the spaces between the flutes (or ridges) of metal roof panels and is then covered with a rigid board. The metal panel roof can be mechanically fastened or bonded to both layers. Under the metal roof, the EPDM membrane is bonded to the rigid insulation or physically affixed to the structural purlins.