How to Choose a Flat Roof
It is common to see flat roofs on commercial properties, but why is single-ply roofing so popular? What materials are best for a single-ply roofing installation? While it may appear that the roof is flat, there is always a small pitch and not 100% flat. This pitch averages between ¼ to ½-inch per foot to allow water drainage.
There are several types of single-ply roofing materials to choose from. Each type is commonly used but provides differences best in certain situations. Below are the most popular types of single-ply roofing materials used for flat roofs, including;
- TPO (Thermoplastic Olefin)
- EPDM (Ethylene Propylene Diene Monomer)
- PVC (Polyvinyl Chloride)
What Is The Best Type Of Material For Flat Roof Installs?
There are a few things to consider when choosing the type of material for a flat roof on commercial property, such as the maintenance required, cost of installation, and overall lifespan. Many roofers recommend PVC roofing in most cases as it is considered the best single-ply material for roofing.
However, PVC roofing materials will cost more than single-ply TPO or EPDM roofing materials. PVC provides various benefits over the others, including being crack and impact resistant. Because of the reinforced membrane that makes PVC stronger, it is not damaged as easily and requires less maintenance. In most cases, PVC roofing materials come with a 20-year warranty by the installing roofer. Also, with PVC materials being white, it reflects heat during the day, lowering overall energy costs.
What Is Single-Ply TPO Roofing Materials?
TPO is created with a single-ply membrane which became popular in commercial use. The TPO membrane is created from a single synthetic layer and made in sheets that come in three different widths: 10, 12, or 20-feet. The sheets are then rolled and delivered on-site to be installed by professional roofers. TRO is used for 40% of commercial roofing systems and reflects UV light. Because of it being cheaper, it is quickly gaining ground on PVC installs.
Which Is Better, TPO or EPDM?
Both TPO and EPDM are good options for flat roof systems, but the geographic conditions should be considered. Factors such as frequently hot weather, hailstorms, rain, or other conditions like solar panel installation. Both types of material will work in colder climates as they are mechanically-fastened, and both may be fully-adhered for durability. However, there are a few differences to consider, including:
- UV Rays:EPDM will retain heat, while TPO reflects heat
- Seam Fusion: EPDM seam tape, TPO hot air gun
- Attached:EPDM is mechanically attached, TPO is chemically done
- Color Choices: EPDM only comes in black; TPO has multiple options
- Historical: EPDM 60 years, TPO 20 years
- Lifespan: EPDM 25-30 years, TPO 15-20 years
How Long Will Single-Ply Roofing Last?
Due to single-ply membranes designed for commercial being made to be flexible and come in pre-fabricated sheets, they are guaranteed to last. The single-ply roofing materials are flexible, durable, strong, and these are factors that make them better than traditional materials.
Installation is more efficient because of the attachment methods used by roofing contractors. With regular maintenance and proactive inspections, the lifespan of single-ply roofing materials can be up to 30+ years.
TPO – Thermoplastic Olefin Single-Ply Roofing
The thermoplastic membrane of TPO uses scrim reinforcing with a 35%/65% thickness between two layers. The top layer has UV stabilizers and roof pigments, among various lifespan-extending components. Meanwhile, the bottom layer uses components that offer consistent welds. TPO has up to a 25-year warranty with a life expectancy of up to 30-years for flat roof systems.
PVC – Polyvinyl Chloride Single-Ply Roofing
PVC is also a thermoplastic membrane that uses scrim reinforcing between two different layers, with an equal thickness. The top layer has UV stabilizers, cool roofing pigments, among various lifespan-extending components. Meanwhile, the bottom layer uses components that maintain a consistent weld of both layers. PVC has a warranty of up to 25-years on commercial buildings and a 30-year or more life expectancy.
EPDM –Ethylene Propylene Diene Monomer Rubber Single-Ply Roofing
EPDM has a rubber-like membrane that only comes in black. It is often applied completely adhered with glue but not reinforced. EPDM has a 40-year warranty with a 35-year lifespan expectancy. However, the warranty is voided if rook leaks are caused by standing water resulting in failed seams.
Commercial roofing is not as simple as it seems; there are many factors and components to consider. If you are asking how to choose the best flat roofing materials, it is recommended to choose a reliable commercial roofing contractor first. Let us help you choose the right roofing materials for your commercial building; call today to speak with a professional.