Underlayments provide extra protection for your roof by keeping your roof deck safe from water penetration. There are many different types of underlayments that are designed with a range of features. For example, there are synthetic felt, synthetic, tile & metal, wind/ice & water, and self-adhering styles of underlayments. Felt or traditional underlayments are your basic or originals. Synthetic underlayments are a modern take on roofing. They are spun or woven polypropylene or polyethylene and polymer that creates a reliable weather barrier that is made to be installed between the roof deck and roof material for an all-over protective weather barrier. Tile and Metal underlayments are made to withstand high temperatures for under tile and metal roofing. Wind/Ice and Water underlayments are made to withstand winter weather conditions for those homes located in areas with heavy winters. Self-adhering underlayments (also known as self-stick underlayments) are backed with an adhesive for a simple and quick installation with the capability to seal around nails and withstand rough weather. Many underlayments have many different features, it all depends on what is needed for your roof.