How to Use Poles As Rafters

Select poles which are at least 6 inches in diameter. Thinner poles will not bear the weight of the roof system.

Mill a flat surface on the top edge of the poles. The roof deck boards should rest on a flat surface, not on the round surface of a pole. Use a hand plane, or a portable saw mill to create a flat surface, approximately 4 to 6 inches wide on one surface of the pole, which will be installed facing upward.

Frame in the gables at each end of the roof line. The gables support the ridge board that each of the pole rafters will butt into. If a pole is used for a ridge board, this ridge board pole should also be planed to create flat surfaces that point upward at angles to one another, which mirror the roof deck surfaces.

Miter the top end of the pole rafter with the reciprocating so it meets the ridge board in a vertical joint. If a round pole is used as a ridge board, the ridge pole and the pole rafters should be notched so the rafter fits into a pocket in the ridge pole.

Lift the rafter into place so the flat milled surface of the rafter faces upward, toward the roof decking.

Miter or notch the bottom end of the rafter that rests on the exterior wall with the reciprocating saw. The point at which the rafter rests on the exterior wall must be cut to create a flat surface so it distributes the weight of the roof system onto the exterior wall evenly. The pole should be notched to create a flat surface 3 to 4 inches wide. The rafter pole can be securely fastened to the wall at this point.