Tar and Gravel or Built Up Roof (BUR) System Issues

Tar and gravel roofs have been around for over a century. They are a low cost option which is commonly found on low-slope Commercial and Residential buildings.

Built Up Roofs (BUR), more commonly referred to as Tar & Gravel roofs, are created by installing several different layers of asphalt and roofing felt, fiberglass, or hot-mopped tar with heat. The system is then covered with a top coat (flood coat) of gravel or rock meant to protect the underlying layers from the elements such as solar exposure, wind, and hail. The rock also provides additional weight to help hold the roof in place and often times varies in size.

The reason this roof system is more affordable than others is, when it comes to roof systems, you honestly do get what you pay for.

The common issues with this type of roof system are:

  • The system is prone to leaking as the rocks can often time cause as many issues as they are designed to prevent. These roofs are not designed to hold the standing water which so commonly exists on rooftops in the state of Colorado. With standing water on a roof system you will often times be at risk for mold.
  • Identifying the source of a leak is extremely difficult. Water travels as it enters the roof and may be identified in the ceiling at a much different point of entry than the initial puncture in the roof.
  • Once leaks are finally identified, they are much harder to fix. Moving the rock or gravel around on the roof, when attempting to find or fix the leak, often times causes several new leaks.
  • The additional weight of these systems can be problematic, especially when combined with the added weight snow brings in the winter seasons.
  • Most large commercial roofs require seasonal maintenance. Not necessarily to the roof system itself, but to the different items on the roof i.e. (air conditioners, solar panels, cell phone towers). Foot traffic of any kind can and will cause punctures on these roof systems.

Replacing these roofs has become increasingly popular in recent years. When replacing a Tar and Gravel, or BUR system you usually have a few options.

  1. Where acceptable, you can remove the top layer of gravel, and overlay the system with one of the newer more commonly installed systems like a single-ply membrane i.e. (TPO, EPDM, or PVC). If the building is in a location where only one layer of roofing is allowed, this would not be a viable option.
  2. You can remove the top layers of gravel and then coat the entire roof system with a silicone coating. This will provide you with a seamless roof system and in most cases give you a comparable warranty to any single-ply system on the market. This is probably the least labor intensive and lowest cost option.
  3. Lastly, you can remove the system completely giving you the option to re-install any of the above mentioned newer systems. This is clearly the most expensive option as it is very labor intensive.

Regardless of which option you select, MBis here to help you get it done. We will provide you with competitive quotes for any roof repair or replacement. Please contact us directly for a complimentary inspection. We look forward to working with you!

We deliver honesty and integrity back to the roofing and construction industry, with owners who truly care about our customers' best interests.