What is TPO Roofing?

TPO (thermoplastic polyolefin) and PVC (polyvinyl chloride) are thermoplastic single-ply roofing membranes that have heat-welded seams. Both are considered ‘cool’ roofing materials and may help improve energy efficiency and reduce cooling demands. They’re also installed using a similar process. The differences between the two materials lie in their chemical formulas. Both are designed to conform to the movement of the roof; however, PVC and TPO have different performance characteristics. PVC is often selected for applications where chemical resistance is a priority and may offer greater flexibility in certain applications. TPO and PVC have different cost and performance characteristics, and TPO is often selected when project budget is an important consideration.

More on TPO Roofing Materials

TPO, a single-ply (meaning one-layer) roofing membrane is one of the fastest-growing commercial roofing products on the market. These types of roofs are incredibly popular because they’re generally simple to install; they’re also incredibly versatile and durable. These factors make TPO roofing materials a commonly selected option for many commercial buildings.

TPO roof membranes come in sheets that are 10, 12 or 20 feet wide. Your installers will choose the appropriate width to minimize the number of seams on your roof. Reducing the number of seams may help reduce potential points of water intrusion, so this is a way your contractor helps minimize your risk of leaks.

Some of the other benefits of TPO roofs include:

• Water-resistant characteristics when properly installed
• Reflective surface that may help reduce solar heat absorption and UV exposure, which can damage building components
• They’re made from a single layer of synthetic materials and reinforcing scrim and are commonly selected for commercial roofing applications
• You can choose what type of insulation you want to use with TPO roofing materials
• Certain TPO roofing assemblies may achieve Class A fire ratings depending on the product, assembly design, and testing standards, and there are fire retardant chemicals added to the product during the manufacturing process

How Can TPO Roofing Save You Money?

Particularly when compared to black roofs made from materials such as EPDM, TPO roofing reflects UV rays and heat from your building. TPO roofing may help reduce cooling demands and improve energy efficiency. Project costs vary, but TPO is often selected when budget considerations are important.

TPO Roof System Installation

TPO is a durable yet cost-effective membrane designed for commercial and industrial single-ply systems. TPO is known for its:

• Cost-conscious roofing option
• Ease of installation
• Energy efficiency
• Thermal expansion properties

Many people choose TPO roof systems because installation may require less labor than some alternative roofing systems, depending on project conditions.

Insulation on TPO Roofs

All roofing materials need some type of insulation. With TPO roofs, you can generally choose from:

• Polyisocyanurate, or Polyiso. Polyiso is a commonly used insulation type, and although it’s more expensive than other types of insulation, it has a higher R-value rating.
• Expanded polystyrene, or EPS. EPS is commonly used on roofs, walls, and floors because it can provide a favorable balance between insulation performance and cost. It can even be used for ground contact, and it doesn’t retain water over time, which makes it an attractive choice for many commercial building owners.
• Extruded polystyrene, or XPS. XPS insulation is generally blue, green or pink, but you won’t see it through your roofing materials. This is a middle-of-the-road insulation when it comes to price and performance, and it’s semipermeable.

What is R-Value?

R-value is a measure of how well a material resists heat flow. The higher a material’s R-value is, the more capable it is of insulating. R-value is incredibly important when you’re choosing commercial roofing materials, because the thicker your insulating layer is, the more thermal resistance your roof will provide. If you’re insulating a roof on a building that must remain cold, for example, you’ll want an insulation with a very high R-value and thickness.

So what R-value do you need? Your commercial roofing contractor will guide you, but here’s a quick look (Insulation requirements vary based on building type, climate zone, applicable codes, and project requirements.):

• Attics need between R-30 and R-60
• 2×4 walls need between R-13 and R-15
• 2×6 walls need between R-19 and R-21
• Floors and crawl spaces need between R-13 and R-40

For your purposes, depending on the specifics of your building, the appropriate insulation value will depend on your building, local codes, and project requirements.