Before applying asphalt shingles, the first step would be to?

Applying felt underlayment is the correct first step before installing asphalt shingles. This felt serves as a protective layer between the shingles and the roof deck, providing essential weatherproofing. It helps to prevent water infiltration, which can occur if rain or snow penetrates the shingles. The felt also acts as a barrier against wind-driven rain and can reduce the likelihood of direct water damage to the roof structure.

In the roofing process, felt is typically rolled out and installed before the shingles to ensure that there is an additional layer of protection. Once the felt is applied adequately, the other components, such as flashing in valleys, vent hoods, and eave drip flashing, can be installed appropriately over the felt and under the shingles. By prioritizing the felt application, contractors help ensure the longevity and integrity of the roof system.