What is a Built Up Roof?

There are so many different types of roofing options readily available to home and business owners like. So many that actually making a choice on the type of roofing to install on your property can be a lot harder than most people expect. Many people would prefer installing wood shakes or asphalt shingles for their sloped or gable roofs but these are not viable options when you have a flat roof. What type of roofing is a good option to consider when planning a new roof for your flat roof?

It may seem like there are limited options when it comes to flat roofing but when you actually look at different materials in the market, you’ll find that there is just as much variety in the kinds of flat roofing as there are in sloped roofing – maybe even more!

What Is A Built Up Roof

Choosing the type of flat roof to install on your property is no easy task. An easy way to go about it is to look around your area and observe the different kinds of flat roofs. You’ll easily see that there are quite a few common options around. One material that is quite common when you look at flat roofs is built-up roofing material. Built-up roofing is also known as a BUR system is actually suitable for either flat or sloped roofs but is more commonly used for flat roofing or low sloped roofs. Whether you are picking a roof for your home or business, this type of roofing is also suitable for both residential and commercial properties, although it is more frequently used in the latter.

In order to understand all the perks that a BUR system provides, it is best to answer these questions.

  1. What is built-up roofing?
  2. What are the types of built-up roofs?
  3. What is the lifespan of a built-up roof?
  4. Why should you choose BUR?

What is built-up roofing?

A popular roofing option way back in the 1970s, BUR roofs are also known as gravel or tar roofs because they are made up of alternate layers of tar, coal tar, reinforcing fabrics and bitumen or asphalt. At the top, the roof is finished off with an aggregate layer made of stone or gravel. Reinforcing fabrics that are often used include fiberglass or organic mats. At the surface, other materials are also incorporated to add certain properties. These materials include hot asphalt, elastomeric coatings, fibreglass, mineral-surfaced cap sheets or aluminium coatings. It’s the most suitable option for flat roofs and buildings with low slopes as it creates a continuous sealed surface.

What are the types of built-up roofing?

There are 3 different types of built-up roofing. These are Ballasted Asphalt Built-Up, Hot Built-Up, and Cold Built-Up.

Ballasted Asphalt Built-Up

Ballasted Asphalt BUR systems are not anchored to the roofing membrane. While this may seem like the roof  would not be stable, it is actually still a very durable and long lasting roofing option. The surface of this type of roofing has loose gravel which is spread over the deck. Strong winds may seem to threaten to move the gravel and expose the underlying material, however this will not happen because the stones and gravel used for this purpose are large in diameter. To ensure excess movement, a thick layer is applied with plates and fasteners in various locations.

One of the advantages of this type of roofing is that it is easier to install and can actually be put together in any weather condition making it a good alternative if you’re looking to get a quick installation under usually unviable conditions.

Hot Built-Up

Hot BUR systems undergo a liquefaction process. Thus, it is termed “hot” built up roofing because of the process of melting the materials during installation. This process makes it harder to install because roofers have to work with heated materials. However, the advantage is a more compact and sleek roof. 

Cold Built-Up

This type of BUR can be sprayed on or applied with a squeegee. No toxic fumes are involved, and changes in weather conditions don’t affect its application.

What is the lifespan of a built-up roof?

There are different types of BUR systems and each one offers a different lifespan. However, the average lifespan that you could get from this type of roofing is between 15 and 30 years. This will also be highly dependent on the materials used and the usual weather conditions of your area. When installed properly, some built-up roofing systems can last up to 40 years. 

BUR systems last longer in warmer climates than cooler ones. The lifespan of this type of roof is comparable to that of another common roofing option – asphalt roof shingles – which also last up to 3 decades on average.

Why should you choose BUR?

Here are some great reasons why you should choose built-up roofing for your property.

  1. Exceptional Durability
  2. Ease of Maintenance
  3. Excellent Water Resistance
  4. Fire Retardant
  5. Energy Efficient

It is essential to understand the materials and the type of roofing you are choosing before having it installed on your roof. With a built-up roofing system, its durability and longevity depend highly on the materials used, type of installation, and the workmanship of your roofers. If you’re thinking of replacing your roofing system, consider BUR as it’s an option that’s been tested by many property owners but you have to make sure you hire an experienced professional roofing contractor, like our team at Waddle Exteriors, as we will do the job properly the first time.

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