At Absolute Commercial Roofing in Loveland, we help customers understand how to choose the right building material for a flat or low-pitched roof. There are many advances in technology and technique that make our professionals able to provide your commercial building with a roof that will look great, protect your interior from leaks and last for years to come.
So, if you have a flat or low-sloped roof, many of the more traditional roofing materials will not work for you because a flat or low-sloped roof needs to help move water off the roof and withstand any pooling of water that occurs. Traditional roofing materials used on a flat roof are sure to have leaks in a very short period of time.
You may be wondering why anyone would build using a flat or low-sloped roof, given the known issues with leaking. It is important to know that commercial flat roofs are sometimes used when additions are done, to avoid awkward-looking roof pitch eyesores. For commercial buildings especially, flat roofs offer a huge convenience by allowing items, such as HVAC units, to be placed on the roof instead of taking up valuable and usable commercial space on the ground.
Why Use a Membrane Roof Type?
Membrane roof types are particularly important for buildings that have flat or low-sloped roofs. Though flat and low-sloped roofs have been around for ages, they can be highly problematic. First, the main reason a large majority of roofs have a substantial slope to them is to avoid issues with water. On a roof with little to no slope, surface tension and gravity will pull the water into the smallest crack or crevice. This will create a leak in the roof. Membrane roofs are made to avoid leaks and to help the water run off of a flat or low-sloped roof. Such roofing is commonly used on buildings, particularly commercial ones, and tanks.
Sheet Metal Membrane
Metal roofing has been around for a long time. Technology has allowed for some improvements on this already durable material. Sheet metal membranes or systems can be very long lasting. They are generally quite durable and can go as long as 25 years.
Asphalt used to be the only roofing material type up until around 30 years ago. Its use now is waning, though it is still can be an option with some roofing companies. It is sometimes called tar and gravel roofing but is generally, now known as BUR (built-up roofing).
Essentially, tar is mopped in multiple layers onto felt paper. This type of roof can be messy and difficult because it requires significant skill to produce a leak-proof roof. The advantage of this type of roof is that it can withstand foot traffic, which is not something all materials can do. This type of roof can also withstand heavy collisions.
Lumber Sag and Crown
Flat roofs used to commonly be built on top of wooden structures. Over time, the wood may sag and the sagging can be compounded when the lumber itself is not level. Keeping this in mind will be important because it can be quite difficult to find a roofing membrane that will work for this kind of roof. Water may have a tendency to puddle on this type of roof, regardless of the membrane used, unless something is done to correct the sag issue.
These types of membranes started to appear as early as the 1950s. Synthetics are based in various rubber or plastic products. Prior to the appearance of these products, every flat roof owner would expect to deal with leaking at some point. The appearance of synthetics made this assumption questionable and in some cases completely avoidable. Synthetics now have expanded to a wider variety of materials and even managed to improve substantially over time.
Flexible Roofing Membranes
Flexible roofing membranes can also be considered the right material for a flat or low-pitched roof and come in three main types. Each type is fairly complex and has different processes to produce them with some variation in advantages. Overall, these types of membranes have become more reliable, have increased their design flexibility, and lowered their costs since they were first introduced.
- Thermoset Membranes: These flexible roofing membranes chemically cross-link. That means that once the seams cure, it is as if you have one giant molecule as your roof, which is a great advantage. A number of the synthetic rubber roofs are a part of this category. Thermoset membranes are fairly thick and withstand a wide range of exposures over time. EDPM, CSPE, CR, and ECR are all considered to be thermoset membranes. Some of these membranes can be quite cost effective.
- Thermoplastic Membranes: These membranes do not involve chemical cross-linking or any sort of vulcanization, but they are very similar to thermoset membranes. With thermoplastic membranes, the seams are welded together using heat or solvents. Properly installed welds can be as strong as the material itself. This group includes PVC plastic materials, as well as a number of others: CPA, CPE, EIP, NBP, PIB, and TPO. Some of these membranes, such as PVC, can also be very energy efficient.
- Modified Bitumen Membranes: These membranes mix asphalt with modifiers as well as reinforcement materials. They are often referred to as a “sandwiched” roofing material. This category of membranes is also referred to as “torch-down” roofs because a large torch is used to melt the asphalt and this process is what joins the seams together. This type of membrane does not always have as much leak-free service as some of the other types of roofing membranes but one advantage is its multi-ply membrane which makes them durable.
When it comes to the right material for a flat or low-pitched roof, a roofing membrane can provide all the protection you need for your commercial property. Knowing a bit more about the membranes will give you some ideas about what might best suit your needs. There are a wide variety of membrane options available. Come see us at Absolute Commercial Roofing in Loveland to discuss which of the many roofing membrane types may be perfect for your commercial building needs.