The purpose of roofing underlayment is to serve as an additional barrier or protection for a roof. As the roof ages and is exposed to the harsh weather environments water may get under the shingles leaking into the building causing damage and wood rot. With an additional layer of protection the chances of this happening is reduced greatly.
Synthetic felt has just about completely replaced the old 15# and 30# tar paper that used to be installed on almost every roof across America. Synthetic felt is lighter, more durable, and much easier to work with. It is about 7 times stronger than the tradition 30# felt yet is about 10 times lighter. Here at Code Engineered Systems we typically install GAF Felt Busters or Owens Corning RhinoRoofing U20.
Peel & Stick Underlayment
Peel & Stick roofing underlayment composed of a rubberized asphalt waterproofing compound, reinforced by fiberglass making it much tougher and more durable than traditional felt paper. Peel & Stick is a self-adhesive modified composite underlayment allowing installers to simply roll it out, peel off the tape, and allow it to stick directly to the deck. Unlike traditional felt paper Peel & Stick creates a watertight barrier for the roof as it seals the deck and around the nails. In the event that a storm blows off a few shingles, peel & stick underlayment will stand up to the job waterproofing your home as wind and rain can’t be blown under the overlaps and run into the nail holes as with felt paper. We install peel n’ stick all all roofs with a pitch of less than 4 in 12. Typically we install Resisto Self Adhered Watering Membrane or GAF WeatherWatch®