Built Up Roofing

Built Up Roofing Systems have good waterproofing characteristics but suffers from a loss of ductility after prolonged exposure to UV.

Common Issues


Roof Ponding – Water retention on a low-slope roof caused by inadequate roof drainage or structural deflection.	Alligatoring – Cracking of a built up roof producing a pattern similar to an alligator’s hide.

Weathering – Deterioration of a built up roof caused by exposure to weather, thermal expansion, acid rain and UV degradation.	Extreme Heat – Excessive heat build up on dark colored roofs. Temperatures can reach 180°F or more in the summer.

Asphalt degradation is a growing concern. UV-rays oxidize the surface of the asphalt built up roof and produces a chalk-like residue. As plasticizers leach out of the asphalt, the asphalt built up roof becomes brittle. Cracking and alligatoring inevitably follows, allowing water to penetrate the system causing blisters, cracks and leaks.

Oftentimes, a complete tear-off is not necessary. Before you succumb to the expense and hassle of roof replacement, consider Built Up Roof Restoration instead. If you have a small but persistent leak problem, you may be able to do Built Up Roof Repairs yourself. For help in product selection, visit Built Up Roof Coatings.

Perform annual inspection and repair any damage immediately. Penetrations like vents, pipes or ductwork can open up and may need to be re-sealed periodically. Blisters or delaminations should be cut off and repaired since they will leak over time.

Leaks in built up roofs are difficult to isolate and a seamless built up roof coating system is the best alternative to roof replacement.

What’s a Built Up Roof?

A built-up roof or BUR is a class of low-slope roof that consist of layers of reinforcing felt between either asphalt or coal tar bitumen.

A lot of old buildings with low slope or flat roofs are topped with built-up roofing made from layers of asphalt-coated roofing felt. The top layer is usually covered with rock or gravel, which serves as a ballast to hold the roofing material down and protect it from UV damage. Built-Up Roofs with gravel surfacing are also known as Tar and Gravel roofs. Typical lifespan of a built-up roof is 10 to 20 years depending on weather conditions.

Types of Built Up Roofs
- Built-Up Asphalt Roofing
- Ballasted Built-Up Roofing
- Cold Applied Built-Up Roofing
- Built-Up Coal Tar Roofing
- Tar and Gravel
- Glass-Fiber-Reinforced Asphalt Emulsion Roofing
Solar Reflectivity of BUR

The solar reflectivity of BURs depends on the color of the surface layer. Four BUR surfacing options are aggregate, smooth, mineral cap, and protective coating.

Black asphalt roofs can reach 180°F or more in the summer. High temperatures and UV-rays accelerate asphalt degradation. The heat load of a black roof can severely degrade the performance of rooftop air conditioning equipment. To make matters worse, the heat build up raises plenum temperatures thereby increasing cooling costs in the building.

Elastomeric coatings provide the highest reflectivity and is a very popular option for building owners. White roof coatings can reflect up to 90% of the heat from the sun.

Built Up Roof Restoration

Add 10 or more years to your built up roof with our Built Up Roof Restoration System. Get a seamless roof without costly tear off and disruption. Stop roof leaks and prevent further degradation.