Instead of just having an open porch installing a porch roof will enable the homeowner to be able to use the space during times of rain or intense sun.
Roof support birds notch.
In this diy guide you will learn how to install a roofing joist or rafter that includes how to work out the pitch of a roof cut a ridge or plumb cut at the correct angle work out the correct length of joist you need and the exact location for a birds mouth joint how to correctly cut a birds.
Adding a roof onto an existing porch can add a lot of character to the front of your home.
If you re framing a gable roof on a new house or building a shed or even a doghouse with a gable roof you ll need to cut a number of roof rafters.
In my porch roof rafter photo above the bird s mouth notch wanted to be rather shallow an effect of a rather low slope roof.
Simple jig to cut your birds mouth notches.
Before you cut your boards you ll need to measure the width of your building and calculate the exact length of each rafter.
After all it s the job of the walls to hold the roof up.
Stakes go down about 18 to 24 could also use a permanent steel or wood posts in place then just build around it if your not changing out the footing.
Due to the width.
The actual design of the bird s mouth cut will vary in both length and depth according to the width of the top plate the angle of the roof the design of the roof overhang and also the use of framing connectors.
To illustrate a 2x12 rafter that meets the irc s d 4 notching limitation cannot have a notch deeper than 2 13 16 inches 11 1 4 divided by 4.
By cutting a birdsmouth notch those forces are redirected downward onto the wall plate and wall which is exactly where you want those forces to go.
This prevents the rafter from potentially shifting causing your roof to sag or worse collapse inward.
But using the width of the top plate to determine the length of the seat cut can also get you in trouble.
Birdsmouth joint how to cut a birdsmouth and how to cut and install roofing rafters and joists.
As the roof pitch increases so does the likelihood of overnotching.
Possibly the most satisfiying part of the roof yet.
