Beginner's Guide To Flat Roof Systems

Whether on commercial or residential buildings, flat roof systems are common in high density areas throughout the US. Though flat roofs do the same job as asphalt shingles, for example, they also use different materials and have unique strengths and weaknesses. If you have a flat roof on your home or business, it’s important to know about the pros and cons, as well as signs that your flat roof is in need of repairs.

Here’s the beginner’s guide to flat roof systems:

Flat Roofs Aren’t Truly Flat

“Flat” roof is a misnomer. No roof is 100% flat because water needs to be shed. Therefore, flat roofs have a slope of at least 1/4 inch per foot. This is enough to guide the water towards the drainage system.

The Aspects of Flat Roof Systems

As we said, you commonly see flat roofs on industrial, commercial, government, and public structures. There are reasons for this, and we’re going to look at these now.

• Structure – Such buildings tend to be utterly immense, which makes pitched/slanted roofs not impossible, but highly impractical and difficult to implement them. Flat roofs are much easier (and often safer) to implement across such vast amounts of space. It’s also more affordable.
• Additional Space – These sorts of structures need a lot of ventilation and HVAC components, which have to be mounted on the roof. With a flat roof, these massive installations are more sound, and much easier to put in place. It’s also easier to repair/replace/maintain such equipment with a flat roof.
• Ease of Maintenance and Inspection – Flat roofs are much easier to inspect, maintain, and repair on such large structures. Massive area-covering pitched roofs would be a nightmare to deal with, and in cases where such roofs exist to that scale, this has been more than documented over the years.
• Efficiency – Flat roofs tend to be very energy-efficient, which is a major concern with such immense structures. There have been recorded savings of 30-40% with flat roofs. Also, a primary ingredient of flat roofing, atactic polypropylene (APP) is a recycled byproduct, which is environmentally sound.

The Cons of Flat Roofs

So far, it sounds like the benefits flat roofs have to such large commercial structures, should translate nicely to an average home, with similar, scaled-up benefits. This isn’t entirely untrue, but there are some downsides to flat roofs that you need to consider before going all in with this.

For one, they require a lot more maintenance than slanted roofs, due to their flush exposure to the elements. The less modular nature of the materials means that repairs can be more arduous and costly in some cases as well.

They’re more likely to develop leaks more quickly than other types of roof and are more prone to ice dams, and debris builds up as well. They have, therefore, to be cleaned more often, and de-iced in harsh winters.

Flat Roof Types

Not all flat roofs are the same. There are in fact a few different types of these roofs, and let’s take a quick look at some of them.

• Built-up Roofing (BUR) – This is the most common type used in industrial/commercial structures. There is a layer of waterproof membrane (usually fiberglass or an advanced synthetic), and some tar and gravel as a sealant. These have been used in residential applications as well because they’re affordable and relatively resilient. However, the sealing liquid is quite noxious, and the gravel can cause drainage clogs if you’re not very careful.
• Rubber Roofs (EPDM) – These are far more common for residential use than BUR. They consist primarily of a rubber-type layer, which self-adheres to the metal/gravel underlayer. It’s regarded as very easy to install/replace, but seams like to form int his, it can shrink in cold weather, and leaks can develop quickly.
• MBS – Modified bitumen systems are becoming a favored alternative to the previous two types. These are specially-formulated layers that seal and bond without the use of hot liquids or other noxious substances. They’re very cost-saving and have less of the seam/leakage/shrinkage problems that EPDM roofs have, and don’t have the loose, clogging materials that are common with BUR.

Get a Flat Roof System From RGB Construction

Now you know more about flat roofs, including some material types and their strengths and weaknesses. If you’re looking for a flat roof system for your commercial or residential property, give RGB Construction a call. We’ve been in business for over two decades, helping business owners get the most out of their roofs.