Extending A Roof Rafter With Cleats

Secure each tile with two large head roofing nails.

Extending a roof rafter with cleats.

A good estimate for a contractor to do this same roof overhang extension would range from 50 to 85 per running foot. Choose to extend the preexisting rafters to add 2 9 inches 5 1 22 9 cm. 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. A birdsmouth cut involves taking a notch shaped like a bird s mouth.

Pictured at left is a 2x6 rafter spliced together using 3 4 plywood. This cost did not include any labor or waste disposal fees. The gravitational forces on a roof cause the rafters to want to push outward. 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.

Structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes. Lay all tiles within 1 foot of hips ridges and abutting vertical surfaces in roofer s cement. 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. 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. The cost of extending my 30 foot long roof overhang 14 inches was 340 or 11 50 per running foot for materials. Use cleats the same length as the width of the new rafter when added to the width of the old rafter. 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.

If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center. 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. As such it s important to have rafters properly secured so these forces don t win out. In this case the rafter as a whole is actually stronger than it would have been because the splice is more than adequate and the plywood adds to the strength.

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. Attach 1 2 inch wood cleats to both sides of the existing rafter. Double the tiles at eaves and project them 1 inch over the rear edge of gutters.