I am building a wood chip and clay wall system, only timbers are ridge and ridge posts and braces, (2 floors 17' tall, 24' span) Has anyone built with only the "form walls"( ie no timber frame) 2 story??

It sounds like a lot of wall for no structure in it. Are you using Larson trusses in the wall system? I have a 20' wide timber frame, 2 full floors in the works. I hear the chip walls are tough, but are they that tough? Why not a full frame?

Tim

Cost and time are the main reasons for no frame. You can easily build a one story building this way, with let-in 1x braces. Can a person make mini shear walls at the corners with the 1x bracing all the way up to the plate. I have not heard of the larson trusses. There are problems with using plywood for shear too. First, if applied on the inside of the outer wall, you block off the stud bays to be filled. This wall system is supposed to breathe. If you apply it to the outside, what does the plaster attach to? many questions??

What is the make up of your "form walls"? You are bracing from the plate into what? A standard 2x framed wall? Larson trusses are like ladders attached to the frame, 2' centers. One stringer of the ladder is inside and the other is outside. You can attach lath to the inside and siding on the outside.

Where do you get your clay?

Tim

Clay and chips have poor resistance to shear - such walls are infill only, not meant to be load bearing. If you wish to stick frame a wall, use Larsen trusses, etc, that structure needs to be able to bear the loads all by itself.

Adding sand to the mix would give you greater shear resistance, and if you add enough, pretty soon you are building a cob wall, which is fine without a frame, but going 2 stories means a lot of material lower down - maybe 3' thick walls at the foundation. I've heard recently of people adding pumice to their cob mixes to improve it's lay-ability, and this apparently greatly increased the amount that can be placed with slough-off.

My $0.02