Need help building trusses


In the Brooder
12 Years
Sep 27, 2007
Maryville, TN
My coop is 4'x8'. I am using 2x4's. After I have the footers and framing done I need to build my roof. I have no idea how to go about figuring the angles to cut my rafters (I think that is what each piece is called), and I don't have a clue as to what length to cut each piece so they meet in the middle. When I get the framed walls up the coop should be 4' wide from outside to outside meaning the outside of each frame board. I am no good at geometry at all. I can tear a piece of electro-mechanical piece of equipment apart and rebuild it, but this cutting and angles just don't click in my head so please make this as elementary as possible.
What you could do if you have a piece of plywood is start at a corner and mark 2 foot at the bottom of the piece. Your marking 2 foot because that is the center of your roof. Then for example you could mark 2 foot up the side of the piece and using something straight connect the to marks. Next measure the length of the line which is the length of the rafter and both angles are 45 degrees. Thats an example of cruisers roof.
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I was thinking of having each rafter screw flush with each frame board. I have sheets of tin roof I was going to use so I could let them hang over about 6 to 8 inches. I am thinking I would cut each frame board at a 45 degree angle, so each rater at one end would need to be at 45 degrees. I think where each piece joins in the middle would need to be 45 degrees also. If I am correct with all my thoughts there. I would need to know how long to make each rafter measuring from longest edge. 45 degrees is just a guess. What I need is enough slope so water runs off.
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I am confused, are you doing rafters or trusses? They are different things.

From your description above it sounds like you mean rafters. Trusses would probably be easier for you. You just have to have somewhere HONEST TO GOSH TOTALLY FLAT to build them -- like a good flat patio slab or driveway. You lay the 2x4s out in the appropriate pattern and mark and cut them so they butt together and then attach the parts with some sort of gusset or plate. (Normally I would say 'use plywood gussets, not those metal truss plates' but for a 4x8 coop the metal truss plates should be *fine*.)

Google for 'truss designs for shed" or something like that, or just look at peoples' shed or coop plans.

The advantage of trusses are mainly a) you lay out the angles on the ground, so can do some of it by eye and it's easy to mark your cutting lines; and b) as long as you build them all identically -- leave the first one lying there and build each other one atop that pattern so they really are identical -- they are pretty easy and no-brain, then you just put them up atop the walls and scab together temporarily with a 2x4 til you can attach the roof sheathing.

Good luck, have fun,

You don't want more than 2-3" *maximum* of unsupported roof tin, so you need to extend the rafters (or trusses) *themselves* out beyond the walls if you want a 6-8" roof overhang.

Too much unsupported length of tin is a real risk for catching a gust of wind and peeling the whole thing off the roof. You don't want that

Have fun,

Sorry guys I thought a truss was the whole piece together on each side and a rafter was just on one side. I think I know the difference. What I think I meant to way was truss. Suburban Chick Farmer 09 has me cutting each truss at 34". I also did't know how much to let hang over so I just guessed at 6"-8". I will go with 2". I just want the rain to run off the rook and not to damage the coop itself.

I think what you guys are calling a gusset is a brace so to speak or a piece that is cut at the same angles where the 2 trusses meet so you can screw the trusses together.

I believe rafters are pieces going straight across from one side to the other. I suppose they are used as some type of support.

Do I need to put a board in between each wall stud near the top as support or will everything be good without?

Do I need a board in between each truss as support?

I really appreciate this. I hope to be able to get all this information from my head to my hands. LOL
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I was trying not to confuse you. You had mentioned you wanted a roof like cruiser so I explained an example of how she did it I thought you somewhat understood it from your response but didn't know how to do it so I figured the rafter length for you. I figured that if you cut 1 and looked at her pic you would get it. Im a Union Carpenter and was trying not to get to techinical so you didn't get confused sorry if you did.

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