What is built up asphalt roofing? Built up roofing is usually made from materials consisting of multiple layers of asphalt and reinforcing concrete materials. These layers make a strong finished membrane attached to the underside of the building’s roof structure.
Traditionally, asphalt shingles are the most common materials used for this type of roofing systems. In most cases, asphalt shingles are applied on the roof surface via a roller that forms a continuous and flat coating over the top layer of the roofing material. The roller is then pulled up and pushed back down again, while the uppermost layer of the shingles – the plywood layer – is left out to allow it to bond tightly to the roof structure. Natural rubber or felt is then laid atop the asphalt layer. Natural rubber or felt is a better choice than asphalt, though, because it is less permeable than asphalt.
Fiberglass or rubberized tar membranes are also widely used for this type of roofing system. These materials can be rolled over the existing roof surface, while encapsulating existing building materials to make them nearly impossible to leak through. Natural rubber and felt is usually used as an additional layer over the tar membrane. As a result, these roofing systems are often more expensive than asphalt shingles.
What is built up roofing? In addition to what is already discussed above, what is commonly called coiled-coil shingles, are layers of thin sheets of asphalt that are stacked one atop the other. Often times these coiled-coils are fashioned like burlap, or even paper. They are stacked in a single file or clusters called bituminae, and some form of protection, such as corrugated iron, is applied to make them somewhat less penetrable by water. Bitumen is also sometimes added to these coiled-coil layers in order to improve their fire retardant properties.
The final layer in what is commonly referred to as coiled-coil shingles is the thicker, heavier plies. Most often these plies are made out of PVC. However, there are also instances where people use coal tar plies, which are also fire retardant. Usually these are incorporated within the larger tile or shake roofing system. These types of roofs are usually installed by professional roofers.
What is built up roofing, then, can be defined as the final layer added to a traditional roofing system. This final layer serves to further protect the asphalt materials used to install the roof, as well as protect the final surface from the elements and to improve its fire retardant properties. While the exact materials used to install what is commonly referred to as coiled-coil shingles vary by application, the end result is always the same: a roof that protects the building it covers while providing adequate protection against the elements. What is built up roofing, then, can be considered one of the most advanced types of roofing systems available today. Because of its inherent safety features, what is built up roofing has become a popular option for new construction projects as well as retrofits.