4 ply roofing systems combine 4 layers of felt that are adhered together complete with a flood coat of bitumen with embedded pea gravel to create a protective roof membrane for your structure. 4-Ply BUR systems are widely used and have been a trusted roofing system for our team for over 175 years.

How many layers does a built up roof have?

Built-up roofing systems are most commonly applied with three or four layers of roofing materials to make up the complete roofing system. These layers are typically a base sheet, a fiber sheet, and then either one or two layers of bitumen.

How do you build a built up roof?

First, contractors attach base sheets to the roof’s subsystem using roofing nails. Then, they use tar, concrete, adhesive, or asphalt to glue down felt over the top of the base sheeting. Next, roofers install a layer of gravel or cap sheets, which they then cover with a final layer of asphalt.

What is considered built up roofing?

ARMA defines a built-up roofing system as a roof where multiple layers of asphalt alternated with ply sheets (felts) are applied over the roof deck (vapor retarder) and, most often over insulation that is attached to the roof decking.

How thick is a built-up roof?

between two to four inches
How thick is built-up roofing? A BUR roof system comes in multiple layers, most often between two and four. The thickness depends on the materials used and the number of built-up roofing layers applied, but typically the selvage area ranges between two to four inches.

How much does built-up roofing weight?

The weight of a built-up roofing system can range from about 2.5 pounds per square foot for a smooth surface to 6.5 pounds per square foot for a gravel surface. Though not nearly as heavy as a slate roof or a clay tile roof, built-up roofing is generally heavier than asphalt shingles, TPO, PVC, and metal roofs.

How thick is built up roofing?

What is a 3 ply roofing system?

A 3-Ply Hybrid BUR differs from other membrane options due to its combination of a 1ply base sheet with two plies of glass felt that enhances the performance of the membrane with a quicker installation time and less weight on the roofing system itself.

How thick is a built up roof?

How much does built up roofing weight?

What is the difference between built up roofing and single ply roofing?

Built-up systems are installed by alternating layers of asphalt or tar and supporting fabrics directly onto the roof. You can choose the number of layers (or plies) that are installed. Single-Ply Membrane Roofing Systems have been the go-to roofing for commercial, industrial, and manufacturing facilities for decades.

How long should a built up roof last?

20 to 30 years
In general, a properly installed built-up roofing system will last 20 to 30 years.

What is 4 ply roofing?

The 4-ply asphalt and gravel roof system consists of plies of felt embedded in asphalt and a flood coat with gravel at 400 lbs per 100 sq. ft. These roofs are generally insulated from the roof deck up. Contact MJ Roofing for more information on the 4-ply roofing system.

What is built up roof system?

A built-up roof, most of the time referred to as BUR, is a time-tested roofing system typically comprised of hot tar and gravel. It is made up of many layers and typically the top layer is where the tar and gravel lie.

What is a built up composition roof?

A built-up roof is typically composed of alternating layers of bitumen with reinforcing fabrics and insulation. A final coating seals everything in and competes the process. The layers of insulation are called ply sheets, and they are usually reinforced with fiberglass or an organic material.

What is built up roofing?

Built-up roofing is the most popular material used on low-slope roofs. It’s composed of several layers of bitumen surfaces and is finished up with an aggregate layer or coating. Built-up roofing is nothing new. The concept been around for over 100 years, although it’s certainly evolved during that time.