Building Cathedral ceiling roof truss
 

Hi All

I am planning to build a cover for my patio. I want to have a cathedral ceiling type of effect. I am looking for some plans for building "cathedral Ceiling type roof truss that will be structurally sound. I live in Ottawa Canada so lots of snow in the winter.

Thanks

Don (cdc1505)

Hope this helps.

http://www.askthebuilder.com/B348_Sc..._Design_.shtml

I have used the wood I beams in most of my construction BCI beams that you can order from homedepo. They are made for floor trusses so they are Very strong but are only 8" to 20" thick depending on how many ft you plan on spanning. the ones I use are 14" I think for 24" to the ridge beam and I have a metal R panel roof with 3/4" aluminum backed partial
board. The beams are 2.5 Lbs / ft and are easy to walk up a ladder with one end by yourself and set. they are quick and easy to use. the BCI engineers will make sure you have the right size for your application.

roof
 

A truss is a prefab thing made in a factory.
Framing your own roof uses rafters.
Rafters don't prevent the walls from spreading apart under load so collar ties (horizontal boards that span between rafters on opposite sides of the room) are used.
Finished, this gives you a flat spot from underneath. (The ceiling goes up from a wall, flat across the center of the room, and down again on the other side.)

Scissor trusses provide a peaked ceiling from below but at typically half the pitch of the top truss member.

What you need is a stout ridge beam and strong ridge poles. If your ridge can carry the whole snow load without sag, the rafters only hold up the plywood. Think of a 14" tall, 3" wide glue lam. The exact size depends on the span.

Buy a big ridge, cut the rafters tight to it, and finish the rafter bottoms from beneath.