What is TPO Roofing?
A common question that many roofing contractors have to answer from clients is what is TPO roofing? Everybody has seen TPO roofing at some point in their lives, even if they didn’t realize it at the time. Commonly found on the tops of commercial buildings and is distinguishable by its bright white color TPO is a highly effective plastic-based single-ply membrane roofing. However, like many other offerings within the roofing industry, TPO often has some overlooked features as well as a long list of pros and cons inherent to its chemical makeup. So in order to answer all of your questions and save your roofing contractors some time, we’ve compiled this extensive article on TPO:
What Do We Mean by Single-Ply?
When a roofing material is referred to as single-ply that simply means that the material is made of rubber or other synthetics that can be in someway adhered, fastened, or ballasted to existing insulation to create a better barrier of protection for your commercial or industrial facility. As any contractor can tell you better protection means less damage to your property, as well as better heating and cooling bills, meaning more money in your pocket.
While the concept of single-ply roofing is well known to anyone with even a passing knowledge of roofing materials, a little known detail is that there are several different varieties each designed to fulfill a certain need and meet a certain budget. There are two exceptionally common forms of single-ply roofing Thermoplastic Polyolefin, commonly known as TPO, and Ethylene Propylene Diene Terpolymer, also commonly known by its initials EPDM. As each name implies they are different in their chemical constitution, installation methods, and energy efficiency.
So what exactly is TPO roofing?
TPO single-ply roofing is a polymer roofing material that comes with numerous advantages over other similar offerings such as EDPM in a plethora of situations. TPO is in fact so versatile and high-performing that it is the single fastest-growing commercial roofing solution currently on the market and has been so since its introduction in the 1990’s. TPO is particularly sought after due to its ability to be installed over pre-existing flat roofs resulting from its single synthetic layer construction that is reinforced with scrim.
A Thermoplastic polyolefin tpo shingle is manufactured in several different sizes ranging from 10-20 feet wide. After manufacture TPO is rolled to be easily transportable to the commercial and industrial facilities where they will be installed. TPO is also sought after within the roofing industry for its naturally UV reflective construction. This UV reflectivity has given TPO a reputation for having better heat reflectivity and energy efficiency. It is through this reputation that since its introduction TPO roofing has gone on to gain a colossal 40% share of the industrial and commercial building roofing markets.
The first step to installing TPO roofing is the preparation of the substrate. Usually this entails the removal of the previous roofing solutions, but in some cases can be as simple as cleaning the already installed roof. After the substrate is prepared Insulation is installed to help with the energy efficiency of the building. Just as there are different solutions for roofing materials, there are many different options for insulation, each with its own strengths and weaknesses:
- Expanded polystyrene (also known as EPS) Has the highest R-value rating* per dollar of any insulation currently on the market and is able to be used for insulating floors, roofs, and walls alike. EPS is in fact so durable that it can even be used for ground contact applications where it will not retain water.
- Polyisocyanurate(also known as Polyiso) Polyiso is the most commonly used kind of insulation in the roofing market and is slightly more expensive than a few of the other options available. Nevertheless, even with this added cost, those who employ the use of Polyiso are known to quickly recuperate their costs through the higher R-value the material provides.
- Extruded polystyrene (Also known as XPS) projects where XPS has been employed are usually discernible by the vibrant color of the insulation, with pink, blue, and even green being common variations. XPS is a very middle-of-the-pack offering with performance and pricing that is commonly found to be in between that of Polyiso and EPS. A unique trait of XPs is its semipermeability resulting in a perm rating of one.
After the installation of the insulation the TPO roofing membrane can be affixed to the cover board via the usage of a bonding adhesive, or through mechanically fastened means. After the membrane has been rolled out the contractor will return to use a heat gun to heat weld the seams between the shingles together in what is typically an extremely fast and effective manner.
*Note- An R-value refers to the ability of a material to resist heat flow. In roofing and other building techniques requiring insulation products with a higher R-rating is often pursued to help lower heating or cooling costs.
Pricing for both labor and materials for the installation of a TPO roofing membrane is typically around $3.50 to $7.50 a square foot when the average was determined from roofs about 20,000 square feet in size that employed the material. When compared to other roofing applications In the industry this means that Thermoplastic polyolefin TPO shingles are a remarkably cost-effective offering.
Nonetheless as with any construction material in order to get the best bang for your buck there a few things you’ll need to consider:
- While this typically goes without saying, the size of the area on your roof that you need to cover with TPO is one of the biggest factors in deciding how much you’ll pay for the installation of the material, with the larger the area equating to larger and larger costs.
- As previously stated, TPO must be attached to a substrate, whether it be the material beneath an existing roof, or onto an existing roof itself. This means that the better the condition your roof is in, the more likely you’ll be billed for less prep work.
- A commonly overlooked source of cost when installing a new roof is how easy contractors can access your roof. This is because not only to contractors have to get up to your roof to install new materials, but they also need to transport large loads of materials with them. Therefore the easier the access, the less you’ll be charged.
- Most roofs require some form of insulation to be installed before the roofing membrane to ensure some sort of energy efficiency and although TPO has a Resistance to ultraviolet and ozone chemicals, this rule does still apply. As we’ve previously mentioned different types of insulation carry different price tags, and can therefore play a large role in the cost of your new TPO roof.
- Like insulation, the kind of membrane you choose can affect the cost of your roof.
- There are two ways to install TPO as a commercial roofing solution. The first way is to follow a mechanically attached route that employs fasteners that tend to loosen and break down over time leading a requirement for regular maintenance. The second is via a hot air weld that is quick and extremely effective and requires less maintenance than the other option, though as a trade-off is slightly more expensive. Whichever method you choose will affect the cost of your new roof.
The number of penetrations in your roof can also adversely affect the cost of your new roof. This means that for every vent, pipe, or duct the installation of your TPO roofing membrane will be more complex and will consequently cost more simply to install. Likewise, the penetrations can help lead to leaks and degradations that are costly to repair.
- What kind of warranty you have on your TPO membrane can hugely affect the cost of your new roof in the long run. Those with less comprehensive warranties will likely find themselves shelling out more often for repairs and maintenance. Likewise, those with more comprehensive warranties will find themselves paying slightly more upfront, but are likely to recuperate the extra charges in saved maintenance in the long run.
Advantages of employing TPO roofing
If you follow proper installment and maintenance procedures a polyolefin TPO single-ply roofing membrane will last up to 30 years before reinstallment is needed. Even so, longevity is not the only advantage to using a single-ply membrane roofing solution:
It’s cost-effective – TPO is perhaps the most reasonably priced offering currently available to roofing contractors and clients. This is especially true when compared to other low-cost offerings who do not hold up near as well or over nearly as many advantages in instillation or durability.
You get to choose the kind of insulation you want to use – one of the biggest advantages of using a single-ply roofing solution is that it does not rely on a single insulation solution, meaning you, the customer gets to decide which kind is the best for your budget, needs, and space.
It’s class A fire-rated – TPO and EPDM membranes can easily achieve a class-A fire rating from the underwriter’s Laboratories if flame retardant chemicals are added during the manufacturing and installation processes. This is a big boon to those in storm and wildfire-prone areas as it offers more protection against those hazards.
It can be used as a roof deck – Due to its waterproof nature and immense durability, TPO is an exceptional choice to create long-lasting roof decks and other rooftop settings.
It’s highly reflective or incredibly heat retentive – TPO is often lauded over other roofing applications for its highly reflective nature that stems from its bright white color. On the other hand, TPO’s cousin EPDM is often described as black due to its dark color that is known to retain heat.
Disadvantages to using TPO
– While TPO is commonly known for its inexpensive nature and bright white color, not all companies produce great roofing. Indeed the actual quality of the TPO membrane can vary wildly between companies and even between shipments. To mitigate this risk its best to employ a roofing contractor with a proven reputation.
– Some cheaper TPO roofs are known to crack, shrink, and otherwise deteriorate over time with some cheaper roofs struggling to last into the 10-20 year range even with proper installation and maintenance.
– The range of sizes that TPO comes in is relatively small in comparison to other commercial roofing solutions. This size restriction means that though you can purchase incredible lengths of material, you are likely to have copious amounts of seams between them. Seams are considered detrimental to the roof’s durability, as more seams mean more potential weak points.
How TPO roofing can save you money
TPO isn’t just a pretty addition to your structure, but can actually help to save you money in the long run:
– The most common distinguishing feature of TPO is the bright white color that it draws its highly reflective nature from. While often considered little more than an aesthetic feature TPO’s white coloring and reflective nature actually do serve an important purpose in the material’s resistance to heat. Since the white color helps to reflect UV rays, less heat energy enters the structure that the roofing membrane is on, helping to lower the energy needed for cooling during the summer months, and in turn, helping to lower your cooling bill.
– Due to its plastic nature, TPO roofing is incredibly durable, and resists corrosion and mildew buildup, leading to less need for regular maintenance, and helping to keep the cost of your roof’s general upkeep nice and low.
What is TPO roofing? TPO is an incredibly cost-effective, durable, and effective way to add a roof to your commercial building and offers a degree of customizability in installation and insulation that is unmatched by any other material on the market today. Adding to these advantages is TPO’s ability to save you money on cooling bills in the long term and its ease of maintenance. So what are you waiting for? Get yours today!