I am trying to understand the thermal bridging question with regard to steel SIPs.



Can someone explain the difference to me regarding thermal bridge for the following two scenarios:


1. Building off site a regular framework of 5 1/2 " light gauge steel stud panels ,18 or 20 gauge, (16" o/c), 4-8-12' sections, cavities  filled with PU insulation , and  one or two electrical chases per channel. After installing on site  by normal methods, adding an exterior  cladding of OSB, moisture barrier, and a layer of 1-2" of EPS.

or

 2. Utilizing a product like Thermasteel or Platinum Advanced Technologies which both seem to be engineered with EPS between steel studs without an internal external connection  and utilizes EPS as the insulation.


In the first case scenario I believe the exterior cladding would prevent the bridge but perhaps not as effectively as the spaced non connected stud design in commercial products.

I would appreciate any insight.

Thanks.

Clancy

Clancy;

there is basically no difference between senario #1 and platinum walls they are basically studs filled with foam.
I have looked at the thermasteel details and it is not as bad as the wall section connection points appear to be the only solid steel thru the walls
both #2 senarios need sheathing, while OSB or plywood will both conduct thermally thru steel or wood studs. A solid foam core is the best insulator