I am in the process of building a small shed (10 X 20). One side of the shed is 8 feet tall the other side is 10 feet tall. The roof design is a simple shed roof. I am having trouble with figuring out the birdsmouth cut in the roof rafters. Could someone please give me some instructions in how to determine the measurements for the bird month cuts. If there is another system, instead of birdmouth cuts, I am open to that as well.
Thanks………….
The code requires installing an approved material to slow the spread of fire between floors and adjacent vertical and horizontal cavities — here are the allowed materials and required locations.
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Replies
Ricks
It looks like you have a 2.4 pitch. That is, your roof drops 2.4" for every 12" of run. Get a Swansons speed square with an instruction book and you will be able to make the top cut and birds mount cut.
You get out of life what you put into it......minus taxes.
Marv
There is a time to use math or other figuring, and there is a time to just hold the board up there, mark it, and cut it. Your situation is the latter.
Frame and stand up your 8' and 10' walls and brace them plumb. Make sure the walls are parallel to each other. Hold a rafter board up there on top of 2 top plates. Mark the plumb cuts on the rafter coming up vertically from the outside of the shorter wall and the inside of the tall wall. Mark the level cuts by simply laying a block of wood on top of the wall top plate and tracing a level line on the rafter. The depth of your birdsmouth will be determined by the thickness of the block you use. Now cut your birdsmouths. Check to be sure this pattern rafter fits the way you want it to. Use a torpedo level, or other small level to mark your plumb cuts for your eve overhangs. Use this pattern rafter to trace and cut your other rafters.
Good luck,
Since you are open to new ideas, you could try this:
Cut 2 beveled pieces of wood something like 3.5" X .7" by whatever the hypotenuse is [3.7"?] and nail these on top of your top plates. Then you won't need no birdmouths.
~Peter
The countdown begins, 12 days left.
If you can get the Search thingee to cooperate,Joe Fusco's site has a complete explanation of your question with some great CAD drawings of how to do it several ways.
The string between the plate & ridge board or in your case plate to plate is as good as any book you'll find & he'll answer your questions too if you ask.
Joe H