Measure the width of the ridge beam.
How to extend roof rafters.
Double the tiles at eaves and project them 1 inch over the rear edge of gutters.
Strip off the first 3 layers or more of shingles going up the roof the length of the work area.
You need to get up to the area that you are going to extend.
How to increase rafters for insulation step 1.
Secure each tile with two large head roofing nails.
If you re using a 2x4 it ll measure 1 5 inches 3 8 cm.
The two rafters would not have to line up but that would be simpler for installation.
The ridge beam is the vertical piece of plywood which will form the peak of the gable and to which you ll fasten the rafters on either sides.
At the beam end the rafters are fastened with a 10 inch structural screw through the top of the rafter into the beam.
You could simply support it on the existing wall and install it without a splice.
The blocking is held low to hide the roof wall intersection and to provide a 1 inch air space at the top for a ventilation channel.
These rafters require extra measurement to mesh the hip gable to the ridge beam properly.
If you are.
Then this is not an extension to the rafter but a separate rafter.
Figure the rafter depth needed to provide the desired r value.
Attach 1 2 inch wood cleats to both sides of the existing rafter.
For instance if the roof has 2 by 6 rafters and.
The roof deck is 1x6 attached to the top of the rafters with 1 4 inch space between boards.
Follow safe working procedure falling.
1 or 2 ft.
Lay 10 or 12 inch tiles with 1 inch head lap on the sides of dormers.
Remove the drip edge and the facia trim.
How to extend rafters determining rafter length.
Set up scaffolding.
If the existing rafters have bird s mouth cuts where they sit on the exterior wall plate use.
Subtract the width of your ridge beam.
Lay all tiles within 1 foot of hips ridges and abutting vertical surfaces in roofer s cement.
If the main rafter is only sticking out a short distance i e.