Framing A Shed Dormer Roof

Along the level line and using a square to draw a perpendicular line up to the roof edge of the board.

Framing a shed dormer roof.

Purchase your materials including wood windows and any other specialty. On the roof using the pilot holes drilled in step 1 snap the lines that will denote the opening in the roof for the dormer. Remove the temporary collar ties. Schedule your project considering that the roof will be wide open and the work may last an entire day.

If you feel that your house has little natural light you could think about creating a dormer with shed roof which will certainly help. After the walls ridge and common rafters are set i overlay the valley framing on top of the main roof sheathing to save from cutting a true valley. Make a rafter cutting jig by measuring 12 in. Roof framing doesn t have to be daunting but if it s your first try a simple gable roof say on a garden shed is the best bet.

Cut the shed dormers opening with a reciprocating saw. The end wall of a shed dormer carries the load rather than the sidewalls. However the width can be increased with properly sized and engineered support framing. Framing a shed dormer is a simpler process than building a gable dormer.

If the slope of your dormer roof is the same as your old roof hold a scrap of plywood against the old roof boards and draw a level line on it. To correct a slight dip in the floor we established a benchmark height with a laser level and nailed 2x6 squash blocks to the sides of the existing floor joists. This framing option is usually best for dormers up to 6 ft. The shed roof rafters are fastened to the other side of the header.

Finish the end walls with blocking studs notched to fit around the rafters and fastened to the top plate. Because they can be much wider than gable dormers shed dormers can provide more headroom and therefore more usable space. Shed dormers are an efficient way to gain more space. They also give you more bang for the buck.

Wide depending on the size and length of the existing rafters. Be extremely careful not to damage the existing structure. Usually a dormer is made for extra light into a house. Framing a dormer with shed roof is a difficult process but if you take your steps correctly you will be able to handle the job effectively.

Building a 20 ft wide shed dormer doesn t take much more effort than building a 4 ft wide version.