You can’t find a flat roofing system that’s been around for a longer period of time than built-up flat roofing. Also known as “built-up roofing,” or BUR, built-up flat roofing is a type of roofing system that usually has its top layer consisting of gravel and hot tar.
Besides being the oldest type of flat roofing, it’s also the most common one. BUR is mostly used on commercial, industrial and institutional structures, but sometimes it’s installed on homes. If you’re considering a built-up flat roof, here are some of the benefits, along with a few drawbacks.
Advantages of a Built-Up Flat Roof
There are many advantages to having a built-up flat roof. For example, it’s considerably strong and able to withstand more foot traffic than other types of roofing. Built-up roofs perform well in regions that experience frequent hail storms. They also do a good job of holding up in areas subjected to falling tree limbs
Affordability is a primary perk. As BUR is significantly inexpensive, compared to other roofing systems, it can help save you money, especially when you’re on a tight budget.
These roofs are incredibly safe as they’re highly resistant to fire. Additionally, they’re also offer excellent uplift resistance. Their thermal performance is way above average. In other words, they do a superb job of withstanding extreme temperature changes. This also helps to reduce costs for heating and cooling a building.
Cosmetic appeal is another benefit. Consider that the gravel that’s used on this roofing has a clean, fresh appearance. The gravel also helps to protect a roof from harsh UV sunlight. This is one of the main reasons why many people prefer this roofing system.
Built-up roofing provides superior waterproofing protection. Furthermore, because of its ability to survive inclement Minnesota weather, it offers better longevity than other roofing.
Drawbacks of Built-up Roofing
Built-up flat roofing does have a few negatives. One major drawback is the extreme heaviness of BUR. This is because of the multiple layers that are used to provide ideal insulation. That’s why it’s critical that this roof system is correctly supported to avoid problems.
BUR should not being installed on structures when they’re occupied with people because this can be hazardous. When a building or home needs to be vacated during a roofing installation, it mean that the project can take longer.
Just as any other type of roofing, these roofs also need occasional repair. That’s the time to call a roofing repair specialist. Undulations (surface ripples) are a common repair. This entails adding layers to the top of an uneven surface to make it level.
Another typical repair job done on built-up roofs is fixing open joints. This is done by adding cement to hold down an open seam.
Cracks can occur on a built-up roof. To repair them, gravel and debris must first be cleaned. Next, a small amount of asphalt cement is applied on the affected spot, along with roofing felt, also known as roof plies.
Considerations and Warnings
- You can choose from either a stone or smooth coated surface. A stone coating gives better flood and UV radiation protection. On the other hand, it can be harder to detect and repair leaks on a roof with a stone coating.
- Most built-up roofs can last as long as four decades, provided they’re installed correctly and receive proper drainage.
- Leaks can occur on built-up roofing, usually in flashing areas, such where a chimney and roof connect.
- Another place where leaks often happen are on a roofing surface that has been exposed to heat, cold or too much sunlight as a result of wind blowing away gravel.
- Sometimes, older roofs leak in spots where asphalt has suffered from sun blistering.
To learn more about what type of roofing system is best suited for your home or building, call First Impressions Exteriors. We specialize in residential and commercial siding, roofing, gutters and other services for Minnesota homeowners and business owners. Please contact us and find out about our wide selection of roofing products and services.