With so many types of roofing available, choosing one can be difficult for a property owner. Most prefer either wood shakes or asphalt shingles as they’re two of the most readily available options. But what about properties with flat roofs? The options here may seem limited but they do offer many benefits. One material quickly becoming popular is built-up roofing. Also referred to as the BUR system, it’s suitable for low sloped and flat roofs. This type of roofing is suitable for both residential and commercial properties.
If you can’t make up your mind regarding the most suitable option for your home or business, don’t worry. Our experts have prepared a blog to help you better understand the built-up roofing system and what makes it the best option for your building.
What Is Built-Up Roofing?
Built-up roofing became popular around the 1970s and has since been commonly known as a gravel or tar roof. It consists of alternating layers of tar, coal tar, reinforcing fabrics and bitumen (asphalt), which are finished with an aggregate layer such as stone or gravel. Manufacturers generally use fibreglass or organic mats for the reinforcing fabric. For surfacing, different materials are available, including 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.
Types of Built-Up Roofing
There are three types of BUR, including:
- Ballasted Asphalt Built-Up
This type of BUR isn’t anchored or adhered to the roofing membrane in any way. Property owners were confused about its durability when the material was first introduced. Since it requires loose gravel to be spread over the deck, some worried about a strong gust of wind exposing the area underneath. But 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.
It’s also easy to install since the stones or gravel simply need to be blasted onto the deck. This particular roofing system can be installed under any weather conditions.
- Hot Built-Up
This type of BUR is liquefied during the installation process. This can be more difficult than other types of BUR systems as roofers work with heated materials.
- 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.
This type of roofing has an average life expectancy of anywhere between 15 and 30 years, depending on the materials used and the climate of the region. When installed properly, some built-up roofing systems can last up to 40 years. This type of roofing generally fares better in warmer regions than colder ones. Its lifespan makes it comparable to asphalt shingles which can also last up to 30 years, depending on how they’re installed and the quality of materials used.
Why You Should Choose Built-Up Roofing
Here are some great reasons why you should choose built-up roofing for your property.
- Exceptional Durability
- Ease of Maintenance
- Excellent Water Resistance
- Fire Retardant
- Energy Efficient
While many single-ply membranes can resist ordinary hail, a hailstorm can damage them. Built-up roofing systems can take a pounding from hailstorms without deteriorating much. Similarly, BUR systems are impervious to strong winds and last no matter how long they’ve been in use. Plus, they can’t be punctured by tools being accidentally dropped on them.
Although built-up roofing and shingles have somewhat similar materials, BUR tends to have fewer maintenance requirements. This system is installed in large sheets which have a lower profile than shingles. This ensures that the material is less susceptible to damage and generally has fewer parts needing to be replaced.
The reinforced multi-layer system offers advanced protection against water and reduces the risk of leaks compared to single-ply roofing systems. When this roofing is being installed, the layers of asphalt are fixed together with layers of reinforced fabric above the recovery board layer or rigid insulation. Asphalt is one of the best materials to make roofs water-resistant and is often referred to as the glue that holds the entire roofing system together. It seals the roof and protects it, delivering as much as five times greater water resistance than other roofing types.
BUR roofing – more specifically, ballasted asphalt – has fire retardant properties along with an attractive finish. Cold built-up roofing, on the other hand, is considered more environmentally friendly and doesn’t produce any harmful or annoying fumes. It’s also easy to install, even during extreme weather conditions.
For many years, mineral aggregate like pea gravel was commonly used as a barrier between UV rays and asphalt. However, reflective coatings serve as the ultimate protective layer against the harmful rays of the sun. The white topcoat that’s applied over the surface bounces the rays back into the atmosphere, allowing the property’s interior to stay cool. This helps lower utility costs as you won’t need to use air conditioning as much.
Remember, it’s vital to understand the materials you’re choosing for your built-up roofing system as its reliability depends on them. With modern enhancements, it can offer a durable and long-lasting solution for commercial and residential buildings alike. If you’re thinking of replacing your roofing system, consider BUR as it’s an option that’s been tested by many property owners. Also, make sure you hire an experienced professional roofing contractor as they will do the job properly the first time.