Your roof is a much more complex structure than you may realize. A simple layer of shingles is insufficient as a weather barrier, and in most regions of North America the typical house features a roof with several components including water-resistant or waterproof membranes, possibly some builder’s felt, metal flashing, drip edges, and shingles. Because of the wide range of skills required to properly repair or replace a roof, most homeowners trust a roofing professional to ensure their roof underlayment is appropriate for the job, and correctly installed.
As I have already implied, roofing underlayment involves the parts of your roof that are installed before the outer elements, such as shingles. The advancements in underlayment have been substantial. Initially utilized to provide temporary protection or protection against Ice Migration in some climate zones, this component of your roof now can provide a better barrier to weather, increased protection to your home when damaged has occurred to the shingles, Increased Fire Resistance and Insulation Value. The underlay is generally composed of three layers: felt, synthetics, and barriers.
The felt used in most roofs is asphalt-soaked paper. Paper felt has been used in roofing for several decades, and if you’ve ever seen a roof being built, you will recognize this felt as the black rolls of paper that form the base of a roof. This felt is easily attached with staples and provides an initial, inexpensive layer of protection between your roof and the elements.
In more modern advancement in roofing technology Synthetic polypropylene sheeting has been utilized in the construction of roofing underlayment’s; this material is more resistant to tears and wrinkling than the paper, can allow moisture to pass, and is not adversely affected by moisture, unlike paper based products. The synthetic component of your roof underlayment helps to prevent moisture damage, and it is much safer to walk on than paper felt.
Another improvement in Underlayment’s is the introduction of Self-adhered water barriers. This can be an important aspect of your roofing structure for obvious reasons. The water barrier is generally a sheet with a self-adhesive design to protect against rain, snow, ice, and wind. This layer is especially important when you live in cold or wet climates, but not all roofs are necessarily built with a water barrier. In fact it is possible for just one or possibly all of theseunderlayment’s to be included on your new roof.