Help with rafter design

[rbuck4x4]

Is there any one that can help me with how to lay out a rafter??? I am building a small 4 x 8 coop and need a bit of rafter design help. My front wall will be about 7 foot 5. And the back wall will be about 6 to 8 inches shorter. I also would like to have about a foot overhang both front and rear, same will apply for the two sides. I would like to use the birds mouth for the rafters, but just do not know how to figure all the angles, yes I have tried for a week or more and countless internet hours, so now it is time to get some help from a pro!!!! All of the lengths and heights are written in stone, so wall heights for the front and back can change. Just tell me what they should be to get the proper rafter. I am in North Louisiana. I really need someones help, PLEASE...

 

[JackE]

Save yourself some headaches, and get a few of these:

http://www.homedepot.com/p/Simpson-...lvanized-18-Gauge-Hurricane-Tie-H1Z/100374935

It will be much easier to install, and the rafter will be stronger, because it won't be notched. Then you can just cut the ends off straight, and cap them.

 

[rbuck4x4]

That would be a good option, Thanks

 

[Bryant Redhawk]

I would use two per end of each rafter, that way they won't fold over on you as you block the ends.

Rafter notching is mostly done so the rafter has a seat, the hurricane clips http://www.homedepot.com/p/Simpson-...nized-18-Gauge-Hurricane-Tie-H2-5AZ/100275721 are mostly for holding the roof on during high wind speed events. There is also a different fastener plate we use in the trade which we call a rafter hanger, it is also called a hurricane clip, but is a bit different http://www.homedepot.com/p/Simpson-...lvanized-18-Gauge-Hurricane-Tie-H1Z/100374935

I have sheds built both ways, either way works very well as long as you put spacer blocks in between the rafters to steady the rafters to each other. These blocks also function to keep bugs out.

 

[chiques chicks]

A few years ago I built a slopped roof coop. I just laid the rafters on the walls and toenail screwed using 3 inch screws. I use screws for all construction to pull things together unless the parts being connected are only in compression at all times. I know it's not the proper way, but for what is essentially a simple shed, it works for me. It also created the high ventilation I wanted.

I would never do this on an occupied dwelling, or permanent structure, I don't figure it will last more than ten years.

Strongest wind gusts it's had are around 60mph.