Sol Vista Guide to TPO Roofing

Denver TPO Roofing

TPO roofing is one of the most popular options for commercial buildings and other structures with low-slope or flat roofs. If you’ve seen a flat, bright white roof, it was probably a TPO single-ply membrane.

TPO is one of the main preferred roofing options we recommend for flat commercial roofs, in part because of the reflectiveness and energy-savings it can bring a building.

In this article, we discuss all the important factors to know about Denver TPO roofing.

About Single-Ply Membrane Roofs

TPO is a type of single-ply membrane roof. Single-ply membranes can be ballasted with stone or pavers, fastened with screws and plates, or adhered with commercial adhesives to your roof deck. Some people hear “single-ply” and think the entire roof system is one layer, when in fact the single-ply membrane is just the top layer of many components in your commercial roofing system.

There are three main types of single-ply roofs: Ethylene Propylene Diene Terpolymer (EPDM), Poly Vinyl Chloride (PVC), and Thermoplastic Polyolefin (TPO).

About TPO Roofs


The TPO membrane is installed over insulation and cover board. In Denver commercial roofing, insulation is installed above the steel, wood, or concrete roof deck (as opposed to most residential roofing where insulation in installed beneath the roof deck).

There are a few types of insulation:

  • Polyisocyanurate (Polyiso)– The most popular insulation type for flat roofs, Polyiso is more expensive but brings the best R-value per inch.
  • Expanded Polystyrene (EPS)– With great R-value per dollar, EPS is great for roof, floor and wall insulation. EPS is commonly used to build tapered systems and crickets for flat roof drainage.
  • Extruded Polystyrene (XPS)– Usually with a blue, green or pink color, XPS is in-between Polyiso and EPS in terms of price and insulating performance. Having a perm rating of 1, XPS is considered semipermeable.

A layer of cover board (i.e. DensDeck) is installed over the insulation to add durability and protection against hail.

Finally, the TPO membrane is installed to the cover board either with a mechanically fastened system (screws and plates) or an adhered system (commercial grade bonding adhesives). In some cases, if there is no more than one existing roofing layer, your commercial roofing company can simply install a new layer of membrane over your existing roof.

One of the unique things about TPO roofs is a hot-air welding machine is then used at the membrane seams to weld the seams together for a durable membrane across the roof’s surface.


For a typical 10,000 square foot commercial flat roof, it will cost between $9.00 and $14.00 per square foot to remove your existing roof and replace with a new TPO roofing system.

Some of the factors that can drive this cost up or down are: size of the roof, condition of existing roof, ease of access to the roof (for installers and equipment), insulation requirements, membrane choice, roof penetrations and curbs, and type of manufacturer’s warranty.


Many TPO roofs can last 15-20 years, or even up to 30 years under the right conditions.

One of the main advantages of TPO roofing is the natural reflectiveness of the material. Most TPO is bright white and reflects solar heat and UV rays away from the building. This can save energy cost by reducing air conditioning needs during the hot summer months.

Another key advantage is TPO membranes can bring a Class A fire resistance rating from Underwriters Laboratories (UL). TPO manufacturers add fire retardant chemicals in the manufacturing process to achieve this rating.

How to repair a TPO roof

During a Denver TPO roof’s lifespan, issues can occur such as flashing failure, seams disconnecting, or punctures that will require repairs to be performed.

If a leak has started, it will first saturate the roofing insulation, then the roof deck. That is when you may notice water intrusion inside the building, and you should contact a Denver flat roof repair company to perform a commercial roof inspection. The inspection will reveal: how old the roof is, how many roof layers there are, what condition the seams are in, and where water is entering the roof. We may recommend taking one or multiple core samples on the roof to understand how saturated the insulation is, which will guide the repair options that are available.

Repair Options

  • Minimal/no water saturation – if we have caught the leak early enough, a spot repair may be performed to stop the problem before it gets worse. We always prefer this option, which is why re recommend having your commercial roof professionally inspected (for free) at least once a year to catch problems early.
  • Roof saturation up to 25% of roof surface – if only a quarter or less of your flat roof has become saturated, as determined by core-sampling, your best option is likely to be a silicone coating roof restoration. The saturated areas will be removed and patched with new, dry material, and the entire roof will be cleaned and primed for a silicone coating to cover the entire roof surface.
  • Roof saturation above 25% – if your inspection and core samples reveal more than 25% of the roof is saturated, a silicone coating restoration would no longer be as cost effective or beneficial. In this case, the only option that will protect your building and extend it’s life is to remove the entire roof and replace it with a new roofing system. You can replace with a new TPO roof, or ask you Denver commercial roofer about other roofing options (such as spray-foam roofing).


It’s no wonder why TPO roofing is one of the most popular options for Denver flat roofs. The long-lasting synthetic material, welded seams, and reflectiveness make it a great choice for large commercial properties and even homes with flat roofs.

Annual inspections of your roof are highly encouraged in order to identify any issues early and save money on repairs before it becomes a full-blown leak.

Whether you need a minor repair or a new TPO roof replacement, get in touch with Sol Vista Roofing today to have one of our professionals assess your roof.