Built-Up Roofing Systems: An Overview

When it comes to flat commercial roofs, there are several options when it comes time for a replacement. Built-up roofing systems (BUR) are one option that shouldn't be overlooked during the research phase, as they can be the perfect solution for your roof replacement needs. 

Basic Structure     

There are six layers in a BUR system, which is a major reason why it is so leak resistant. Like all roofs, installation begins with the decking substrate to which the rest of the materials will be attached. Then a layer of insulation is added on top before the first layer of asphalt is smoothed over the roof. 

The rest of the construction occurs in built-up layers, thus the name. A venting cover board is installed over the first asphalt layer and then topped with another layer of asphalt. This is followed by a weather shielding membrane, a third layer of asphalt, and then a layer of roofing gravel. The final coating is with the modified bitumen cap that completes the weather-proof construction. 

BUR Benefits

The most obvious benefit of BUR systems is their weather resistance. The multiple layers help guard against leak formation. Since the roof has a solid bitumen cover, it isn't as prone to wind damage as some membrane roofing options. Further, the surface is very resistant to impact damages, making it a good choice in areas prone to hail storms or high wind events. 

Not only are BUR systems durable in the short term, but they are also designed to be durable in the long term. This means that the roof will last decades before it requires replacement. BUR systems are very low maintenance, as well, and most small damages can be repaired quickly and without a lot of costs. 

Installation Basics

Installation practices will vary, in part due to the type and condition of the roof currently on your building. In some cases, BUR systems can be installed over the top of an old membrane roof if the under-structure and decking are in good condition. Otherwise, the installation will begin with the tearing off of the old roof. The decking may also need to be replaced at this time, depending on its condition. 

Once the base is prepared, then the BUR layers are installed one at a time. The asphalt is left to cure for a short period between layers, so BUR systems will often take several days to put on properly. 

Contact a company like Nolan Roofing to learn more.