If needed shim trusses or rafters to level the nailing surface and install blocking to straighten any warped or bowed top chords of trusses or rafters.
How to level roof rafters.
Run is the horizontal distance that the rafter covers.
Use a tape measure to measure the entire width of your building.
Now take your jack and jack up the ridge.
Set up jack the easiest way to straighten rafters is to jack them into position.
Set the rafter in place carefully allowing for the overhang.
In the gable roof example shown here a rafter with 6 in 12 pitch rises 6 in.
Toenail 3 galvanized wood screws into the lentil.
Damaged roof decking should be repaired by a professional but you can create a temporary solution by following these steps.
When you re toenailing a screw it s important to pre drill the holes before you begin setting the screws.
Cut a piece of 1 2 inch plywood that will cover the area.
You may do this 1 per day and roof rafters can handle more stress.
Jack up until level the frame a wall 16 on center between the 2x4 s that will serve as the top and bottom plate.
To lay out a common rafter you need the pitch of the roof expressed in units of rise per foot of run.
Rick arnold frequent contributor to fine homebuilding and the journal of light construction presenter at jlc live the katz roadshow the remodeling show.
Measure as precisely as possible down to the 1 4 inch 0 64 cm 1 8 inch 0 32 cm or 1 16 inch 0 16 cm.
If these already exist nail a 2x4 to them directly under the 2x4 plate you nailed down before.
Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal.
Mark and cut the first rafter image 1.
Then pre drill the rafter image 2.
Move the jack in increments of one inch to allow for the roof to be able to move with it without cracking.
However the trick to this process is to do it very slowly so it may take a few weeks before you get the rafter into a position where it is straight again.
Before you start cutting you first need to determine how long your roof rafters need to be and the angles at which you ll cut the top and bottom of the rafter.
Our roof rafter calculator tools are handy for calculating the number of rafters needed rafter length calculator lineal feet of rafter board feed in ridge and sub facia and the total board feet in the roof.