Since fiberglass is stronger than steel and does not conduct nearly as much, why not use it for the top and bottom tracks and linings around windows and doors with metal SIPS to reduce the thermal bridges.  Fiberglass is much lighter than steel.  However, it might require a diamond tip saw to cut it.  Has anyone considered using fiberglass this way.  I wonder how fiberglass would price versus vinyl bucks?

By the way, there is a company in Florida that built a home with fiberglass structural members.

Alton;

There are thermally broken channels available for metal SIPs as shown below, but in the southern climates is totally unecessary

Chris,

I did not know that thermally broken steel channels were available.  The home I have been consulting on in Florence Alabama used steel channels for the metal AC Tech panels.  Panels were used for the walls and the ceiling.  A regular wood-framing crew installed the panels with the assistance of factory personnel for the first day.  Very simple and fast installation.  The framing crew now wants to build more homes with metal panels.

Alton C. Keown
Residential Designer and Construction Technology Consultant
Auburn, Alabama
334 329-0957