When hiring professional roofers to install or repair roofs, most homeowners only consider the outermost layer of their roofs. While it’s important to choose the right top layer for a roof, it’s just as important to pick the right underlayment. The underlayment is the layer of the roof that sits just above the roofing deck. It comes in three basic types: rubberized asphalt, asphalt-saturated felt and non-bitumen synthetic. All of these can be installed by a Charleston roofing expert. Although roofing underlayments wouldn’t increase the lifespan of the roofing material on top of the house, it may help to increase the life of the roofing deck.
The most common type of underlayment found on residential homes is asphalt-saturated felt paper. The felt itself can be made from a variety of materials including fiberglass or organic substances. The term “organic” is given to felt that has some kind of cellulose base. While the felt used in this type of underlayment is water resistant, it’s far from being waterproof. The felt usually comes in 30-pound and 15-pound thicknesses. The main difference is that 30-pound felt is much stronger and more water resistant, and it should protect the roofing deck longer.
All underlayment made out of rubber-like material is placed under the category of rubberized asphalt. This type of underlayment generally has adhesive on one side.