Yes, although you may not need old-school, asphalt-saturated felt from days gone by, but you do need a quality underlayment. Felt acts as a moisture barrier and second layer of protection that supports your roofing material. Most manufacturers require some form of underlayment to u003cbr/u003ekeep their warranty valid. They list options that are acceptable for each roofing product. Roofing World only uses a premium synthetic underlayment.