What are rain gutters primarily attached to?

Rain gutters are primarily attached to the fascia board, which is located at the edge of the roofline. The fascia serves as a structural element that supports the rain gutters while also providing a finished look to the roof edge. By positioning the gutters on the fascia, they can effectively collect and direct water away from the roof and foundation of the building, helping to prevent water damage.

The fascia board is designed to bear the weight of the gutters and handle the water flow that is funneled into them during rain events. Other elements, such as rafters, sill plates, and wall studs, play different roles in the structure of a building and are not suited for supporting gutters in the same manner.