Extending A Roof Rafter With Cleats

Double the tiles at eaves and project them 1 inch over the rear edge of gutters.

Extending a roof rafter with cleats.

If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center. To lay out the plumb cut take measurement b from the full scale drawing figure 3c and transfer its dimensions to the rafter on both sides of the centerline of the birdsmouth as shown in. Choose to extend the preexisting rafters to add 2 9 inches 5 1 22 9 cm. For minor additions the contractor can remove the side of the roof and attach additional pieces of wood to the preexisting rafters before refinishing the roof.

If you choose to go with the same width it will be more difficult to execute without a noticeable difference or bump in the roof between the old and the new. The cost of extending my 30 foot long roof overhang 14 inches was 340 or 11 50 per running foot for materials. Part of this has to do with creating a birdsmouth cut to facilitate the joining of top plate and rafter. Lay 10 or 12 inch tiles with 1 inch head lap on the sides of dormers.

This cost did not include any labor or waste disposal fees. A good estimate for a contractor to do this same roof overhang extension would range from 50 to 85 per running foot. When installing 2 by 4 lumber to existing 2 by 6 rafters add the 2 by 4 width which is 3 1 2 inches to the 2 by 6 width which is 5 1 2 inches for a total of 9 inches. Use cleats the same length as the width of the new rafter when added to the width of the old rafter.

A general rule of thumb for cantilevering rafters meaning they will have no vertical support at the ends is to have twice as much rafter attached to the original rafter as the unsupported length. But it is important that the roof pitch is exactly the same as the existing roof because you will see it from one roof to the other if it isn t. Structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes. The gravitational forces on a roof cause the rafters to want to push outward.

Attach 1 2 inch wood cleats to both sides of the existing rafter. It is always better to have a large rafter rather than be concerned with a sagging roof. As such it s important to have rafters properly secured so these forces don t win out. Pictured at left is a 2x6 rafter spliced together using 3 4 plywood.

The height above plate for the hip rafter is the same as for the secondary roof common rafters since the hip falls on the secondary roof plate. Secure each tile with two large head roofing nails. In this case the framer just needed a longer rafter.