There are different types of underlayment that we use, depending on the type of roof that we are installing, and on the application of the roof.
Composition Shingles Roof
Synthetic: we typically install this type of underlayment on all our shingle protects, except when a different one is required. This underlayment is resistant to fungal growth and very resistant to UV damage. Also it is very safe to walk on this underlayment during installation.
Felt: Felt roofing underlayment is one of the oldest types of roofing underlayment. It’s created by saturating paper or fiberglass mat with asphalt. The main advantage of using felt roofing underlayment is cost. Felt underlayment tends to cost less compared to synthetic underlayment. But it is heavier, and more slippery.
Flat Roofing (IB system)
IB Fire Sheet 10: IB Fire Sheet 10 is a fi re resistant Separation Sheet / Thermal Barrier that enhances a roof assembly’s overall fire performance. This material is constructed using a strong fiber-glass core mat that is coated with a specially formulated acrylic coating that can be installed as the first layer directly over a roof deck, as a separation layer over insulation, or as a divorcing layer between a new IB Roof System and the existing insulation or non-insulated roof system.
There are 3 types of underlayment used on metal roof installations: Felt, Synthetyc and self-adhering membrane. We typically install SharkSkin, a self-adhering membrane, unless the jobs specs ask for a different underlayment. Felt and Synthetic underlayments are very similar to the ones described above. Self-adhering Membranes are a high-performance roof underlayment for all metal roofs. They are designed to adhere to the roof deck, and provide protection in high temperature environments. The membrane doesn't melt when the roof temperature is high.