Stud Thermal Bridging

[ki4hpz]

What is best way to control thermal bridging-a stud condutor of head loss or gain in an insulated wall?

[JRR]

You might consider adding (glueing?) a 2" - 3" wide strip of 1" (or thicker) rigid foam to the inside face of the stud.  

[Billy Bob]

Do you think that's really much of a problem?  If I recall,  2"x6" softwood has an R value around 7, and the studs, plates, etc. account for what, about 15% of your total surface area?
It has been suggested previously that instead of plywood one could use rigid insulation to make up the finish dimension on headers, so there's one thermal break working for ya.
I suppose you could glulam studs the same way, with 2"x3"'s and rigid foam, sort of a SIP stud.  I don't know how that would affect the load characteristics, though.  Also don't know if the extra work and expense would give a reaonable pay back period.
How about Homasote or similar insulating sheathing? I think you would have to use plywood in the corners, and maybe additional bracing for shear strength.
All that said, you would probably increase the R value of the wall system more effectively by controlling/eliminating air infiltration, and using an insulating material that has a uniform density throughout the cavities, and which is less subject to thermal drift, (degradation of insulating properties with time).  There have been posts on a couple of systems, including foams and cellulose.  I am leaning towards  cellulose, even though I would have to contract it out.

[lodestar]

I've heard of designs with 2X8 top and bottom plates, 2X4 studs offset from each other...24" oc for outside and inside sheathing...so the 2X4s are really 12" apart, staggered.