What is a built up roof bur?

Built-Up Roofing, or BUR for short, first appeared around the mid 1800’s. It is a roofing system where multiple layers of asphalt get applied between ply sheets (or felts) over the roof deck and insulation.

What is the definition of a built up roof?

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.

What are common problems with built up roofing?

Common problems with these systems include:

• Alligatoring. A series of small cracks can develop in the roof’s surface as the result of shrinkage of the asphalt material.
• Blisters. These soft bubbles form in the roof’s membrane due to moisture trapped underneath.
• Ridges.

What are the layers of a built up roof?

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.

Are built up roofs good?

Built-up roofs tend to provide excellent waterproofing and ultra-violet protection. Thanks to the aggregate top layer, they are also fire-resistant. Built-up roofing is generally low-maintenance and therefore costs little to maintain over its life.

How do you install 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.

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.

Are built-up roofs good?

How long does a flat built up roof last?

A BUR roof (or “built up roof”) is made up of layers upon layers of bitumen and fabrics. BUR roofs provide excellent insulation as well as protection from the elements. Generally, a BUR roof will last around 15 years before signs of age and damage become apparent.