TPO ROOFING SYSTEM (All You Need to Know)

TPO roofing system is emerging as one of the most convenient roofing systems for commercial settings these days. Short for Thermoplastic polyolefin, TPO is basically a single-ply roof membrane that is super handy due to multiple reasons. The TPO roofing system has gained the utmost primacy over the commercial market in the past few decades.

What Is A TPO Roof?

To understand TPO roofing, first of all, let’s hop on what a single-ply membrane roofing is.

What is a Single-ply membrane?

A single-ply roofing membrane is simply a sheet or a layer of any kind of material, for example, rubber, plastic, or any other synthetic material. It can be placed on the roofs of buildings to provide protection and avoid any apparent chemical exposure to the building.

The membranes can be applied to the flat roofs of facilities by various methods including mechanical fastening, chemical adherence, or ballasting.

The single-ply roofing membranes are of two types. The first is EPDM (Ethylene Propylene Diene Terpolymer). The other is, obviously, TPO (thermoplastic polyolefin).

What is a TPO roofing membrane?

Thermoplastic polyolefin is a synthetic roofing material that can be used over low-slope or flat residential as well as commercial buildings. It provides excellent strength and protection against UV rays, fungal outgrowths, unwanted heat waves, and many other environmental factors.

You can think of the TPO roofing membrane as a thick sheet of a thermoplastic material that can extend from 10 to 20 feet. It is stored as a rolled pane that is unrolled during installation.

The outnumbering benefits of the TPO roofing system are at a cost-effective price. Thus, it makes it the most popular and reliable roofing options.

Types of TPO roofing insulations:

Once you have selected TPO as your next project’s roofing system, you need to opt for an insulation type. Different insulations have different properties and pricing and are available in numerous options for the owner to choose from. The following are the types of insulations according to their resistance values against heat and other things.

1. Polyisocyanate (polyiso):

Polyisois a hardened foam board that is made up of synthetic chemicals and materials. If you are willing to pay a few excessive bucks for your rooftop, go for the Polyisocyanurate insulation. It is a bit more expensive than other insulations. However the R-value, i.e. the extent of heat gain and heat loss across the surface of polyiso is really high.

2. Expanded Polystyrene (EPS)

EPSis a polystyrene polymer combined with a foaming agent that expands when heated and hardens upon cooling, forming a firm layer of insulation. EPS has the highest resistance i.e. R-value and is mostly used for walls and ground insulation.

3. Extruded Polystyrene (XPS)

XPS is also a polystyrene polymer that is heated and extruded via a die to attain a certain shape. XPS is a high-performance insulation type that is semipermeable. It has an R-value of 5 which is in between Polyiso and EPS. EPS is really cost-effective and works efficiently in commercial settings.

Why choose a TPO roofing system? (Pros and Cons)

So what makes the contractors and builders go crazy about the TPO roofing system? And why is it getting an unusual prevalence over the commercial market?

The answer lies in the uncountable benefits and advantages that the TPO roofing system has over other roofing systems. Here is a detailed description of the pros and cons of the TPO roofing system that makes it perfect for commercial roofing installations.

Pros of TPO Roofing System

Highly resistant to environmental factors:

After installing the TPO membrane to your roof, you won’t have to worry about various types of rays entering the building facilities. TPO roofing system provides resistance against ozone, UV rays, harmful chemicals, heat waves, smoke, and many other environmental gases.

Other than chemicals and gases, TPO provides protection against dirt and debris accumulation, mould growth, and other bacterial infestations. The smooth and crack-free surface of TPO plates doesn’t allow any matter to retain and grow in there.

Environment-friendly material:

The material of the TPO roofing membrane is made up of chemicals that are environment-friendly and non-damaging to the ecosystem. Unlike other roofing materials that use chlorine as an essential part of their composition, TPO is chlorine-free and doesn’t release any harmful toxins in the atmosphere.

Less energy consumption of the commercial building:

The science behind the low energy consumption of the TPO roofing system lies in the reflective nature of this roofing system. Either white, black, or dark, TPO is designed to reflect heat and light, which causes low heat inside the building. When the heat inside the facility is low, the minimum amount of energy is required inside the building to keep it cool and conditioned.

Extremely Budget-Friendly:

With all the gold and glitter, you would probably think that the TPO roofing system is one hell expensive roofing system to get installed to your commercial buildings. But to your surprise, TPO is relatively cheaper than other polyvinyl roofing systems.

Multiple Insulation Options:

The TPO roofing system doesn’t come with a pre-selected insulation option. Therefore, the customers can choose the insulating material according to their ease, budget, and building type.

Cons of TPO Roofing System

Limited color options:

TPO roofing system comes with very limited color options. This means you don’t have much choice when it comes to opting for your favorite color for your building’s roof. TPO roofing membranes usually are available in white, gray, light gray and blackish shades, so if you’re a color enthusiast, TPO is just not the option for you. If you’re looking for more color options and roof varieties, you might want to check out shingle or metal roofs.

Excessively thick sheets:

The sheets of thermoplastic polyolefin are excessively thick. Though thick sheets would give an impression of being sturdy and durable, but on the contrary, the sheets degrade and weaken over the period of time.

Lack of record and research due to innovations:

The market for roof membranes is not a new one. But the TPO roofing system is a relatively new technology that is just about a few decades old. Moreover, after the introduction of the TPO roofing system in the market, it has gone through a lot of innovations and chemical alterations.

These new trends make it difficult to predict the life span and durability of the TPO roof membrane.

Maintenance and repairing issues:

Despite the fact that the TPO roofing system is quite inexpensive, we can not avoid the issues that can be evolved in case of any wear, or damage to the roof. The installation is economical, but for the repair, skilled professionals are required that will cost you additional money.

The limited life span of the roof membrane:

Unlike many other roofing systems that have more than 30 to 40 years of warranty. The TPO roofing system has only a 15 to a 20-year warranty claim.

How is a TPO Roof Installed?

Thermoplastic polyolefin (TPO) is no doubt a high-performance and low-cost roofing option, especially for commercial installations. And according to the National Roofing Contractors Association (NRCA), it is the most widely consumed system over the last few years.

The installation process is an interesting one and requires professional skills and knowledge in order to make it long-lasting and durable. The various layers of the TPO roofing system include:

  • The membrane
  • The cover board
  • The insulation
  • The vapor barrier
  • The underlayment

The membrane is a sheet of thermoplastic polyolefin that is heat sensitive and molds when welded. It is then turned into sheets of various thickness. The membranes can then be attached via one of the two methods i.e.

  • Mechanical attachment: Mechanical attachment is less expensive and is easy to install, but they have certain drawbacks as they only attach the membranes to the seams.
  • Full adherence: Full adherence, on the other hand, makes use of an adhesive to attach the membrane to the substrate. It is a bit pricey as compared to the 1st method, but the advantages are worthy of being expensive. The membranes fully adhere and give energy-efficient advantages.

Next Steps:

Then comes the cover board, cover boards are the regular boards made up of gypsum that lie underneath the membrane and give a more solid application to the membrane.

Afterwards, the insulating material is fixed, which can be polyiso, EPS, or XPS (discussed earlier in the article). The insulation provides resistance against heat, UV, and ozone. The insulating material can be attached via plates and fasteners mechanically, foam adhesives, or by a combination of both.

The vapor barrier is a solution to one of the technical issues of commercial buildings. When there is a difference in the temperatures of the inside, and outside of the building, vapors tend to move to the lower concentration, which causes moisture retention on the roof. This causes a decline in the R-value of the roof. To avoid this, vapor barriers are installed in the roofs.

Underlayment is optional and is used to increase the fire-resistant property of the roofing system. It is installed beneath the TPO membrane to increase its effectiveness.

What does it take for the maintenance of a TPO roof membrane?

Don’t let the 20-year warranty confuse you, no matter how many years the manufacturer claims to be the warranty of your TPO roof. It can still get punctures, rips, cracks, and splittings. In case of any mishap, don’t panic and get your roof checked by a professional roof inspection team.

The rips and cracks are really hazardous and can cause water leakage into the building.

To avoid this, call the roof inspection team and ask for a complete evaluation of your roof condition. After infra-red inspection, the team will guide you about the repairing options according to the extent of the damage that has been done.

The damage can be evaluated in terms of the saturation of the pre-existing roof if the roof is not so busted and has a saturation of 25% or less. The roofing inspector will allow you to choose an alternating roofing membrane that will fix your TPO roof.

The repair options include:

  • Silicone restoration membrane system: In this method, the ripped edges and seams are cleaned and fixed by a silicone coating. The silicone coating is spread over the whole roof to avoid future damage.
  • Spray foam roofing system: In this method, a liquid is sprayed over the entire damaged roof (after cleaning and power washing). This liquid turns to foam upon expanding and forms a thick layer over the roof, leaving the seams filled and repaired. 

But if the roof has a saturation of more than 25%, then the only option you’re left with is reinstallation of the TPO roofing system.

How much does it cost to get a TPO roofing system installed?

As stated earlier, The TPO roofing system is a relatively reasonable option for commercial facilities. However, many aspects are to be considered before you can precisely infer the amount of money that would be needed for your TPO roof installation.

The expenditure on the TPO roofing system depends on many factors; a brief list of these factors are as follows.

  • Roof area and size
  • Existing roof condition
  • The insulating material is chosen
  • Membrane material selected
  • Installation choice of the owner
  • Warranty and durability of roofing material
  • Factors affecting the roof of the building

As a general idea, the installation of a TPO roof along with material, reinforcements, labour, and other entities would cost you around 3 to 8$ (dollars) per square feet.

Concluding Thoughts:

A strong roofing system is the basic need of any residential as well as commercial building. It is the utmost protective barrier against many environmental factors. So a wise selection of the roofing system and installer is very important. And since thermoplastic polyolefin (TPO) has proven to be a new roofing standard over the past few years due to a considerable number of benefits, it can be the best option for your next commercial project. That being said, make sure to do your research and choose the right roofing contractor to properly install your roof.