Pros and Cons of TPO, MOD-BIT, EPDM and PVC Roofing Membranes

When choosing a roof membrane for your flat roof, you are presented with a lot of options. Like choosing a roofing material was not enough! However, think about the benefits you will get by getting that extra layer for a durable roof. Today, roofing materials like concrete tiles, wood shingles and shakes, slate and asphalt shingles are no longer considered that durable.
What most commercial roofers are offering is a series of membranes that are of high quality and are long-lasting. Amongst these membranes, the ones that have emerged as the clear winners are TPO, MOD-BIT, EPDM, and PVC. Granted, a person who is limited by their budget might find these roofing membranes a bit on the expensive side but the durability offered by these are tenfold, as compared to basic roofing materials.
One of the biggest reasons why these roofing membranes are preferred over traditional roofing materials is because they can be easily applied over flat roofs. As for asphalt and other shingles, they are installed by overlapping one tile over another, which is prone to leakages and is what causes the substrate to rot. The only concern with covering a flat roof with a membrane is that the seams must be sealed perfectly to prevent water from penetrating the inner surface. The following are four types of roofing membranes and their pros and cons:

PVC

PVC is a plastic roof material that is formed by a gaseous reaction between oxygen, hydrochloric acid, and ethylene. It is one of the strongest flat roof materials amongst TPO, EPDM, and MOD-BIT. According to the American Society of Testing and Materials (ASTM), a roofing membrane must have a breaking strength of around 200 PPI. In the case of PVC, it surpasses ASTM’s standards and its minimum breaking strength is 350 PPI. To make sure that it prevents water from penetrating the roof’s inner surface, the seams are welded with hot air. Once complete, the points welded become stronger than PVC itself.

Pros

• Long-lasting
• Extremely strong
• Energy-efficient: White PVC reflects the sun’s solar energy
• Has a lifetime warranty
• Chemical resistant (grease from vents will not affect the PVC)
• Resistant to fire
• Resistant to wind
• Watertight
• Environment-friendly: Can be fully recycled

Cons

• Expensive
• High installation cost
• Requires insulation boards to be installed first
• May crack in extremely cold weather if walked upon

Life Span: 15 to 30 years
Note: PVC membrane should always be installed by a professional commercial roofing company because amateur contracts tie down the ends mechanically, instead of using welding, in order to reduce labor cost.

EPDM

EPDM roofing is usually the second choice after the PVC membrane, mostly because it is cheaper. EPDM is like a giant sticky rubber mat that must be laid down by a professional roofing company to avoid any bubbles. Since there is no welding involved, with time it can become susceptible to leakages.

Pros

• Environment-friendly (is made from recycled materials)
• Economically friendly (saves on cooling cost in summer)
• Waterproof
• Wind and fire-resistant

Cons

• Prone to leaks from chimneys and HVAC units
• High repair cost
• Can be easily damaged
• High installation cost
• Not as strong as PVC

Life Span: 10 to 15 years

TPO

TPO roofing membrane offers the best of PVC and EPDM. It is made by combining ethylene, rubber, and propylene. With the addition of various other filler materials like fiberglass, talc, and carbon filler, the membrane is made stronger and more durable. The biggest drawback of TPO is that since it has been introduced recently in the market, companies have yet to find the perfect combination that will create a strong membrane. Homeowners considering TPO can content themselves with the fact that although TPO does not have the best track record, it has now reached a stage where it can offer them quality and warranty.

Pros

• More energy efficient than PVC due to its availability in black, white and grey color
• Chemical-free
• 100% recyclable
• Will last longer if the membranes are welded at a high temperature
• Durable
• Stronger than PVC
• Wind resistant

Cons

• Poor track record
• High installation cost
• Requires fire-resistant retardants

Life Span: 7 to 20 years

MOD-BIT

A modified bitumen, or MOD-BIT, is a complex roofing membrane and hence, must only be applied by commercial roofing professionals. The multi-ply membrane has a base layer that is attached via bars or plates to the roof. Then, using a permanent adhesive, the roof’s base is sealed and then for the final touch, a granule top is applied for energy-efficient properties.

Pros

• The multi-layer prevents any wear and tear as compared to PVC, EPDM, and TPO
• High tensile strength
• Hail, fire, and wind-resistant
• Long-lasting

Cons

• Requires insulation material to be laid down first
• High installation cost
• Absorbs too much heat
• Heavyweight

Life Span: 10 to 20 years
Choosing the wrong roofing material can become quite expensive if your house’s roof cannot bear the material’s weight. Other factors include weather conditions of the place where you live and roofing contractors available nearby. This is why it is important that you hire a roofing company to perform a roof check and ask for their recommendation. Anderson Industrial Roofing is a contractor that offers commercial, residential and industrial roofing services in roof repair, installation, replacement, and restoration. Having more than 25 years of experience under its belt, the company’s professional roofers have performed several jobs all over Texas. For further information about our services, give us a call.