Modified Bitumen Vs Built Up Roof

A plain tar and gravel roof also referred to as a built up roof or bur is quite different from modified bitumen.

Modified bitumen vs built up roof.

Modified bitumen is a roofing membrane consisting of asphalt and plastic or rubber polymers and is therefore widely considered an evolution of asphalt built up roofing bur. Having worked with most and specified several i can tell you i prefer a built up roof with a mod. Modified bitumen mb roofing is an asphalt based close cousin of the built up roof bur designed for buildings with low slope or flat roof structures. It is more durable tougher and has redundancy you don t get with a single ply.

First although an app modified bitumen roof is designed to resist uv light damage blistering cracking and oxidation a lack of standards led some manufacturers to skimp on the addition of the app modifier. These roof systems are constructed with layers of felt and bitumen that provide a redundancy of durable protection. This caused the roof to underperform. Build up vs modified bitumen vs rubber membrane flat roofing.

January 22 2019 share the wealth. Built up roof membranes bur and modified bitumen mod bit are generally composed of alternating layers of bitumen and reinforcing fabrics that create a finished membrane. Built up roofing the first layer can be adhered directly to the roof substrate. You will never see actual gravel chunks of rock say 3 16 to 1 4 in size on a modified bitumen roof.

Conventional built up roofs bur are known to require a heavy gravel cover significantly adding to the roofing job. Modified bitumen displays the built in redundancy of asphalt built up as well as the uv resistance and flexibility of a modified membrane. Flat roofs are one of the most popular roofing designs and yet still one of the best investments for most of the facilities. Bur roof systems have been utilized for over 100 years in the roofing industry.

If needed a base sheet can be fastened to the roof to create a flat and safe work space. There are 3 main types of flat roofing systems. A single ply just offers a cleaner easier solution but without the longevity of a built up roof. And roofers can pick from three commonly accepted methods of application hot asphalt heat and cold adhesive roofing installations.

This prevent leaks mold and rot all of which can weaken the roofing structure and cause costly damage. This is not a requirement at all for modified bitumen roofing systems. Built up roof bur modified bitumen and single ply. Engineered modified bitumen roofing membranes originated in europe in the mid 1960 s and have been used successfully in the united states and canada since approximately 1975.

However the type of materials used for the flat roofs depends a lot on your locality. Bit cap sheet if done correctly over any single ply membrane. Except for the overlap at seams a modified bitumen roof is a single membrane in thickness over the roof surface. Second although the gravel spread over a modified bitumen roof is intended to offer uv and hazard.