How to Build a Gable Door Canopy

Locate a door header, wall studs or other wall framing outside the door strong enough to support a canopy with a stud finder and design the canopy to fit. Use a tape measure to mark the locations, to extend the canopy beyond the sides of the door with the bottom a foot or so above the height of the door.

Install two 4-by-4-inch posts vertically on the wall at the selected width. Set them plumb with a level and fasten them to the house wall framing with lag bolts, which have a screw end and a bolt head. Drill 3/8-inch pilot holes with a power drill through the wall siding and sheathing into the framing. Drive the bolts in with a ratchet wrench.

Cut two 4-by-4-inch beams to the desired depth of the canopy. Miter two 4-by-4-inch beams at 45-degree angles on each end. Fasten one end of each beam to the top of the wall posts and secure them with the diagonal braces. Use 3-inch galvanized screws driven with a screw gun to fasten these.

Make two pairs of 2-by-4-inch rafters to frame the gable roof. Angle the tops at any desired pitch using a speed square; put the pivot point of the square at the top of a rafter end and align the designed pitch on the "common top cut" line on the square at the board top to mark the angle. Angle both ends, putting the pivot point at the bottom of the board for the end cut. Cut a triangle notch in the ends of the rafters to fit on the top and edge of the side beams. Make all cuts with a circular saw.

Fasten rafters to the side beams with galvanized screws, set the top ends together and secure them with screws. Secure the inside pair of rafters to the wall with lag bolts driven through the rafters into wall framing.

Cover the canopy with 1/2-inch oriented strand board cut to fit the sides., fastened to the rafters with 8d galvanized nails. Extend it just past the rafter edge on the outside and just beyond the side beams on each side. Staple roofing paper over the OSB on both sides of the roof, overlapping it at the peak. Nail on shingles on both sides of the roof and put cap shingles over the peak.

Install 1-by-6-inch fascia or facing boards cut to the same peak pitch as the rafters and nail them to the outside rafter just below the shingles. Cut facing boards to fit between the wall posts and outer facing and nail them to the side beams.