Built-up roofs are a tried and true commercial roofing option, but that doesn’t mean they don’t take planning. While built-up roofs (BUR roofing) systems were invented in the 1800s, and became popular for commercial buildings during the 1970s, they’re still around today for a reason. They’re durable, reliable, and long-lasting!
In fact, built-up roofing constitutes the largest segment of roofing systems in North America, a market valued at over $700 million. That extremely large BUR roofing segment is due to the sheer number of commercial buildings in North America over 25 years of age that have flat roof (thin warehouses, factories and fabrication centers).
So what is built-up roofing, and how does it work? Keep reading to find out!
How Do Built-Up Roofing Systems Work?
Built-up roofing systems are an evolution of the asphalt roofing method. As compared to other roofing materials (such as metal roofs), BUR roofing membranes are created through a layering process of bitumen and reinforcing fabrics. They are most commonly used on low-slope roofs or flat roofs.
When installing a BUR system, there is a layer of bitumen, which includes asphalt, coal tar or cold-applied adhesive that is placed across the roof deck. (If necessary, you can fasten a base sheet before putting this layer on to create a safe and sturdy space to work.)
As it’s covered ply sheets (or roofing felts) of hot asphalt and tar fabric or fiberglass are rolled down. These are typically referred to as “plies.” On the top layer, the surfacing aggregate is then placed for durability and aesthetics. Additionally, a reflective coating can be added to meet cooling requirements.
Because of the several layers of bitumen involved, not only are BUR systems extremely durable (providing high resistance to fire and wind), but they’re also quite heavy.
Built-up roofing solutions also have high reflective qualities (when a reflective coating is utilized), helping to save energy costs and keep inside temperatures consistent.
Built-Up Roofing Advantages
This popular roofing solution has been around, albeit in less technical form, for ages. Commercial buildings benefit the most, and highrises around the world use built-up roofing as a viable and efficient roofing solution.
Why? Here’s a shortlist:
- Excellent waterproofing
- Efficient use of space
- Ultra-violet protection
- Fire-resistance
- Low-maintenance
- Less costly than other systems
Durable Against Harsh Weather Conditions
While you might not typically think of tar as being flame resistant, it takes a lot of heat to cause it to ignite. Along with that, the tightened layering of the bitumen creates a waterproof roof that helps to stop water from finding its way into the building.
With the added aggregate and fiberglass, BUR roofing makes for a very sturdy material. Because it’s so sturdy, you can be assured that your roof will be able to withstand even the toughest weather conditions.
Low Maintenance Roof Membrane
Built-up roofing is typically praised as being a low maintenance option. Still, many owners opt to inspect the system 1-2 times a year to ensure that the bitumen roof is up to standard.
That minimal upkeep, along with its lower costs, makes BUR roofing an excellent choice for building owners who need a roof installation that won’t break the bank.
Energy Efficiency
Today, most built-up roofing systems come with a layer that has high reflectivity. This creates protection against UV rays, helping to maintain a cool building temperature. As a result, you’ll need to run heating and cooling less often, resulting in improved energy consumption.
Built-Up Roofing Disadvantages
Everything has a downside, and BUR roofs are no different. While maintenance is definitely on the low side, it isn’t nonexistent. Some common things to look for during your seasonal commercial roofing inspection are:
- Cracks
- Areas of water pooling
- Blistering
- Undulations or waves
- Open or split joints
These common problems are easily preventable with routine inspection and quick attention from a trusted commercial roofing contractor. Let’s take a quick look and break down some of these common issues.
Split Joints
Open or split joints are where two rolls meet and the seam between them has dried out and separated. The best fix is a replacement, but a more economical path would be a repair using a patch. A qualified professional can assess the situation and determine which option is best – repair or replacement.
Water Pooling
Water pooling is a small problem that can cause enormous issues down the line. Inspecting your BUR roof after strong weather (to check for water pooling or other problems) is a great preventative measure.
Gone unchecked, your commercial roof can crack or leak, which can encourage soft spots and other warping problems, like waving, undulations and blistering.
Blisters
Blisters are often caused by water damage, possibly from too much moisture on the underlayment during installation or a small leak that has gotten worse. On a hot day, the water expands as it turns to steam, forming blisters. There could be one or many, but it’s always a bad sign, as it makes the top layer susceptible to tearing with foot traffic.
All of these things should be dealt with immediately by inspecting the roof inside and out for more than surface damage.
If replacement is necessary, BUR roofing requires that no people are inside the building during the roofing process. This downtime can be costly. Thus, proper inspection and maintenance cannot be stressed enough. Most problems are not critical if they’re dealt with in a timely and professional manner.
Built-Up Roof Systems In a Nutshell
BUR industrial and commercial roofing systems are a great solution for flat roofs, as long as you know what to look for (and know why you’re getting it).
As with most things in life, there are pros and cons. Make sure that you work with someone who knows how to do built-up roofing the right way the first time!
Interested in learning more? TEMA Roofing Services is your premier Akron, Ohio roofing contractor with decades of experience in the industry. Call TEMA Roofing Services today and start working with a trusted roofing contractor.
