Roof Coatings

Different Roof Coating Options for Your Commercial Roof - Torch Down, EPDM, TPO Roofing

Although there are many commercial roofing systems to choose from, there are three specific types of single ply roofing systems commonly installed by contractors across the United States. Of the three types, EPDM is the most popular. It has been used for over 40 years. It is the same synthetic rubber membrane used to make inner tubes.

Another type is TPO, which is a thermoplastic polyolefin membrane, and is probably the fastest growing type of commercial roofing product material.

And finally there's modified bitumen, which is an asphalt based membrane that is similar to a Built-Up Roof (BUR) that is used on many commercial buildings.

Let's look a bit closer at each of these membranes.

EPDM (Ethylene Propylene Diene Terpolymer)

EPDM is an extremely durable synthetic rubber roofing membrane used in low-slope buildings that are susceptible to water ponding issues. It is widely used in the United States and worldwide . Its two primary ingredients, ethylene and propylene, are derived from liquid oil and natural gas.

EPDM is produced in different thicknesses. They are 45, 60, and 90 thousandths of an inch. Most contractors use the industry standard of 60 thousandths of an inch, which is very near the thickness of a quarter. 

Some advantages for using EPDM on a flat roof are:

  • It is the least expensive system to install per square foot
  • It is simple to install with the use of anchors adhesives and rollers
  • It weighs less than other single ply membranes
  • It is sold in wide rolls of eight to twenty feet resulting in fewer seams

Some of the disadvantages of EPDM are

  • Harmful ultraviolet rays degrade adhesive used on seams and flashing causing very premature separation.
  • The black membrane absorbs ultraviolet light causing shrinkage and brittleness, which decreases its life expectancy drastically.
  • Protective mats are definitely needed because the thin membrane is susceptible to punctures due to foot traffic on sharp objects left behind by maintenance crews.
  • Another reason we don't recommend EPDM is because it's so easily punctured. For example, you may see roofers lay out mats for workmen to walk on, and this is supposed to offer protection, but because there's never enough mats to cover the whole roof, there almost always tends to be issues created by the foot traffic.
  • Repairs to seams and flashing is required long before the warranty of the fifteen to twenty years expires.
  • The surface preparation can be an added labor cost when removing an old roof system, or installing one over a pre-existing one.
  • And lastly, the black color of the membrane absorbs heat, and can lead to the super heating of the structure below, causing air conditioning costs to rise significantly.

TPO (Thermoplastic Polyolefin) Roofing

Thermoplastic polyolefin (TPO) single-ply roofing membranes are among the fastest growing commercial roof coating products in the business and have gained praise across the industry for their many performance and installation advantages.

There are two thickness options to TPO; 45 and 60 thousandths of an inch, which is roughly equivalent to the thickness of a quarter. TPO is composed of laminated layers. Of the three membranes, this one requires more experienced roofing technicians and much more equipment.

Some of the advantages of TPO are

  • The seams are heat welded rather than glued, so they are much less prone to separation.
  • The white surface of the membrane reflects much of the ultraviolet light keeping the structure below cooler as measured by infrared instruments as well as basic temperature readings.
  • If the contractor is certified by the manufacturer, to install the membrane, the manufacturer, rather than the contractor, honors with warranty.

Here are some of the disadvantages of TPO

  • The system is fairly new to the roofing industry, about 20 years, and has a long track record of revisions and improvements due to surface and seam failures.
  • Also, TPO is known to shrink and its rigidity causes stress on seams and flashing.
  • A prolonged period of excessive heat exposure causes ultraviolet light degradation
  • Another con is that contractors must calibrate their welding machines very carefully. Improperly welded seams may come loose during the first freeze and thaw cycle and lead to water infiltration.
  • Lastly, the manufacturer's warranty is only fifteen to twenty years.

Installing TPO Roofing

Transcript

mechanically attached roofing system the Versa weld mechanically attached roofing system uses 45 60 72 or 80 mil reinforced membrane field sheets are either 8 10 or 12 foot wide depending upon wind zone deck type and building height step 1 begin by laying the approved insulation with no gaps greater than 1/4 inch versico recovery board and polyisocyanurate insulation with thickness 1 and 1/2 inches of greater utilize a minimum of 5 fasteners and plates / 4 by 8 foot board when using 4 by 4 foot boards regardless of the thickness a fastener and plate are required every four square feet please refer to the details for specific fastening requirements step 2 for the required perimeter secure meant position the four or six foot wide perimeter sheets over the substrate fast in the perimeter sheet according to the required number of fasteners for the project the project requires 12 inch on center fastening versa goes HPV X fasteners plates must be used to fasten the versa weld membrane to the deck position the next perimeter sheet by overlapping the first perimeter sheet approximately 5 and 1/2 inches fasten the perimeter sheet in the same manner as the first utilizing an automatic heat welding machine weld the two sheets together to achieve a minimum 1 and 1/2 inch Heat welded splice step 3 in the field of the roof position the versa weld membrane over the substrate whether using 8 10 or 12 foot rolls when encountering penetrations cut the membrane to fit as tight as possible around the units utilizing the pre-printed X markings along one edge of the sheet install all of the required fasteners the HPV X fasteners and plates are required for membrane securement and lap splices are set at a minimum of 2 inches to achieve a minimum 1 and 1/2 inch weld no mechanical Sherman is required at this location the sheets are typically fastened a maximum of 12 inches on center this project requires 12 inch on center fastening for the field sheets after the sheet has been fastened in place position the next roll of membrane overlapping the adjoining sheet at least 5 and 1/2 inches step 4 complete all splices utilizing an automatic heat welding machine there are 4 details which require additional membrane securement the pre molded and split pipe seal the filled fabricated pipe seal and the versa weld sealant pocket these four details require the use of HPV X fastener plate located 12 inches maximum from the detail round penetrations less than 6 inches in diameter only require four fasteners and plays pipes over 6 inches in diameter will require fastening 12 inches away from the penetration and 12 inches on center heat weld a piece of versa weld reinforced membrane over the plate to achieve a minimum 1 and 1/2 inch heat welded splice past the plate in all directions after the splice area has cooled probe this place and make any necessary repairs to complete the detail apply a bead of tpo cut edge sealant to the edge of the membrane. This is great for waterproofing as properly applied it is highly water-resistant.

The importance of waterproofing all seams and penetrations can't be overstated. Without paying attention to these small but critical waterproofing details, you are almost guaranteed to have water leak beneath the membrane..

You want to have a qualified roofer do this for you, so you might want to check with the Better Business Bureau (BBB) for a bit of due diligence before hiring a contractor.

Modified Bitumen Torch Down Roofing

Now, let us talk about the modified bitumen torch down membrane that has been around since the late 1960s.

Torch down roofing (sometimes referred to as “torch on” roofing) is so named because it requires an open-flame propane torch.  The membrane layers of a torch down roof are made of an asphalt compound called bitumen that is modified with either rubber or plastic.

These single ply membranes can be combined to create a two-to-three ply membrane, that offers the best roofing system to date because there's a forty year guarantee.

Some advantages for installing the modified bitumen membrane

  • It is designed to be flexible in extremely hot and cold weather
  • It is a two ply membrane with a thickness of about five quarters, or three-eighths of an inch, which is very puncture resistant.
  • The membrane surface has been embedded with granular ceramics to protect it from ultraviolet degradation.
  • Seams are fused together with high heat to prevent any separation, unlike EPDM and TPO, the 2 to 3 ply system can withstand a heavy amount of foot traffic.
  • This 2 ply system can be installed over any existing roof or surface with minimal preparation.

There are actually two advantages for installing a new membrane in this case.

  1. 1
    There is no cost for stripping and removing the old membrane and
  2. 2
    Fusing an additional membrane over an old one creates a roof that will last well beyond 40 years, unlike the 15 to 20 year life wear expectancy of EPDM and TPO single ply roofing systems.

Some disadvantages to modified bitumen membrane are

  • The installation requires highly skilled roofing technicians
  • The additional layer has an added costs for labor materials

With a 2 ply system, when torched together, the membranes are fused so well together they cannot come apart and the underlying stones never puncture through. Everybody always asks if a simple base sheet is enough, and it is.  It's a fiberglass reinforced base sheet and it is not going to get punctured. You can walk on this kind of roof material all day long. It's what you want in a situation where there are air conditioning units that need maintenance on a regular basis for example, creating a lot of foot traffic, because it's so extremely puncture resistant.

In conclusion we feel the modified bitumen is likely the best, most cost effective and widely useful roofing repair system for the price. The type and condition of your existing roof does not matter as this is a roofing system that will be cost effective and will outlast any other.

When it comes to commercial roof coatings, you have a lot of options and solutions available to you. Whether your looking at options for a new building or an older one that needs a roof replacement or just a roof restoration service, there are a lot of different application that can be used on your property. And whether you have a metal roof, foam or any other material, a good roofing company can help you figure out if an acrylic elastomeric or silicone spray will provide you the most benefits. Either way, when you add a cool roof reflective coating, your building will need less energy to keep it cool during the hot Arizona summer. Building owners are often shocked at how well these work as a shield against the sun's scorching temperatures, regarding the energy costs and money that they save when these coatings are applied to their roofs when they really only thought they were looking for help with roof leaks.