I am currently designing a timberframe/stick frame hybrid house for a client. The center portion of the building will be timberframed with the wings being conventional stick frame. Does anyone have any general words of advice for these designs? Specifically, I am wondering about timber to stick attachement methods, and differneces in building settling rates over time. The house includes an upstairs which is supported by posts and timber floor beams. In the design as it stands right now, I have beams supported by a timber post at one end and a built-up post (within the exterior stud wall)at the other. Floor joists supported by this are supported at their other end by the exterior stud wall. Do I have to worry about the exterior wall settling and the beam not? Will I have to design some method of allowing the posts to be lowered such as is done with posts supporting floor beams in a basement? Thanks in advance for any tips.
Dan
NEST Timberhome and Design
Clearwater, BC
timberframing and stick framing are really the same thing with different dimensions, and so they are good companions in a building. "settling" will be close to zero in either system. As far as attachment goes, is there any thrust in the equation??
if thrust is present the connection of the timbers and sticks(as well as the timber joinery) should be looked at by an engineer.... otherwise I've always nailed(or lagged) the 2x's into the timbers.
good luck with the design.
Mark's assumption on no settling is kinda dependent on soil type and the size of the footers. Footers with large footprints will settle less than minimum sizes set to just meet local code. If bedrock is readily available at some reasonable depth in your site cushion the footers with some crushed rock and you have a no settle situation. If the subsoil is mostly clay then BIG footprints are really necessary with ratios on the order of 8 to 1 rather than the "normal soil" (whatever that is) on the order of 4 to 1. This ratio is the lower mean diameter of the footprint to the diameter of the top on which you place the sill plate/posts. My present home with a full concrete foundation (6" walls) has 24" footers and it has settled more than 2" in 28 years. This was the code standard at the time it was built (No, I was not the buiilder). My adjacent deck (6" posts) has 40" footers in the same clay and it has not moved in 22 years. I built this one.
Work safe, have fun.
I would look at the orientation of the stick frame members. Studs & posts obviously are not going to shrink much endo, but floor joists, ceiling joists, headers etc, will. If the horizontal timbers & horizontal sticks are roughly the same in dimension & location then the overall timber & stick shrinkage will be about the same. One instance to be aware of is if the timber posts rest on a foundation but the stick frame is stacked on joists that will shrink. Probably not a structural isue but drywall/plaster cracking, doors, etc. might be affected depending on location.