THE BENEFITS OF BUILT-UP ROOFING

LONGER SYSTEM LIFE

Each ply of a Built-Up Roofing system contains a mat of glass fiber reinforcement - most single-ply systems contain no reinforcement at all. When multiple plies are combined and sandwiched between layers of water-resistant asphalt, the result is a longer lasting roof.

LIMITED ROOF MOVEMENT

All roofs expand and contract. Single-ply roofs respond with elongation. But over time these systems can lose their elasticity, resulting in buckling, ridges and splits. A Built-Up Roof, however, limits movement with a high tensile strength in excess of the recommended 200 lbs./sq.in. The potential for fracturing is more or less eliminated, and the Built-Up Roof will last longer.

SUPERIOR WATER RESISTANCE

Multiple layers of reinforcement offer multiple opportunities to prevent leaks. Single-ply membranes only offer one chance at preventing a leak. Plus, there's nothing quite like asphalt when it comes to making a roof resist water. Asphalt is the glue that holds a Built-Up Roof together. It also seals and protects the entire roof, delivering up to five times greater water-resistant thickness.

EASIER INSTALLATION

On a hot Built-Up Roof, the multiple plies are fused together using hot-mopped asphalt to create a monolithic barrier. Every inch is firmly and completely adhered over the entire roof area, without the need for ballast or fasteners. Single-ply systems require ballast or fasteners because they are generally laid loose. But ballast (such as stones) increases structural load and can be blown off by strong winds. And fasteners create less stress points and additional opportunities for moisture leakage.

Coal Tar built-up roofing provides one of the most durable roofing systems known due to its inherent waterproofing and weathering characteristics. Coal tar roofing systems are the time-proven roofing systems for level and low sloped roofs.

Uses
Coal Tar Pitch can be used for the following:

• "Dead" level roofs.
• Water-cooled roofs.
• Low sloped roofs with occasional ponding.
• Low sloped roofs with retarded drainage.
• Buildings with level or low-sloped roofs that are built for long service life.
• Inverted Roof Membrane Assembly (IRMA).
• Waterproofing.

Features
Coal Tar Pitch, the traditional roofing grade coal tar, is manufactured to meet ASTM  standards
Coal Tar built-up roofing systems consist of alternate layers of Coal Tar Roofing Pitch and Reinforcing Felts, topped with a pouring of  Coal Tar into which is embedded an aggregate surfacing.

Slope is the most significant limitation of coal tar roofing systems when compared to asphalt BUR's. When using organic coal tar saturated felts (Tarred Felt), the maximum slope allowed is 1/2" per foot. When using coal tar coated glass felts (Tar Glas), the maximum slope allowed is 1/4" per foot.

Coal tar has a relatively low softening point, so it must always include a gravel surface. Gravel provides many benefits, including protecting the roof from the sun's rays, protection from foot traffic, weight as additional protection for wind uplift, reduced surface temperature, and protection from burning brands. But most importantly, gravel allows us to include an additional minimum average of 70 lb/square of coal tar in the installation of the roof.

Benefits
Coal tar provides superior performance in several areas, giving owners a coal tar roofing system with durability levels that are unique in the roofing industry. Coal Tar has natural resistance to water, air, and water vapor penetration making it impervious to standing water.

Coal Tar roofing is self-healing. Because coal tar has a lower softening point, which allows it to actually flow on warm days. Coal tar can actually heal itself of minor cracks and punctures. This cold flow property is also why coal tar cannot be used on slopes above 1/2" for organic felts, and 1/4" for tar coated glass felts.