roof thrust problem

Personally I would do it just like your little illustration. I would nail the brace onto the rafter itself and down to the joist.. Only 20' wide is not much more than a small shed and the loads have to be small. I'm sure someone will come up with a more complicated way though.

I am encouraged that a barn build this way over a hundred years ago is still standing. Do you remember how often along the wall that the braces were placed? Was it from every rafter (or truss) or more separated. I would think doing it from every rafter would be a bit overkill.

bitternut wrote:

When we specify raised tie trusses we specify that they sit on glide shoes. These let the trusses spread without inducing lateral loads on the top of the wall.

I don't know what glide shoes are and couldn't find a good explanation on the net...the trusses I am using are made onsite and use plywood gussets at all of the intersections. A picture can be found here:

Darryl Bailie wrote:

One option is to balloon frame the walls to the truss support point.

If the walls are already in place then I suggest you contact a local engineer for a solution. The building inspector, if he is alert, will most likely require an engineered solution anyway.

I am using are made onsite and use plywood

your link answers your question "Engineered trusses are designed to transfer any lateral forces directly downward onto the side walls. This eliminates the need for upstairs post and beam supports"

kickstart

You must be able to get something like this in the States

The knee walls have to be able to carry the lateral loads from seismic and wind loading. It's not just a question of the truss and truss connections. Balloon framing is probably the easiest way to go.