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Exterior Wall System


B)  The structural insulated panel system, usually just called SIPS panels, is a manufactured product custom designed to your architectural drawings, built in an offsite plant and delivered to the site in panels and erected.  These panels have an expanded poly-styrene core laminated between two sheets of OSB.  A  typical 5 ½” wall panel gives close to an R-23 insulation value.


C)  One of the manufacturers of the structual steel/insulation system is Therma Steel.  This system works in some ways like the SIPS panel except that you have more flexibility with the height of walls and you have the advantage of a product that can be installed on site without the need for a crane.  Therma Steel's 5 1/2” wall gives you a continuous R-24 but with an effective R-value of 33.


These ideas will be explored in more detail in upcoming interviews. 

High Performance Interview

In the previous videos we have talked about the orientation of your home on its site and the importance of the basement slab and foundation walls being insulated as well as the exterior part of your floor system we call the band board area.


Now lets turn our attention to the exterior wall structure of your home.  More important than the exterior look of your home built with a choice of stone, brick, stucco or one of various types of siding, you need to focus on the wall structure itself and maximizing the sealants and insulation.  Regardless of the

structure used, the goal is to eliminate air penetration and

create as much R-factor as possible in whatever wall thickness

you have.

In this basic presentation, we will touch on three typical high

performance exterior wall systems.


A)  Conventional Framing

B)  Wood Structural Insulated Panels 

C)  Steel Framed Insulated Panels


A)  The problem with conventional wood stud framing with

insulation in the space between studs is the lack of a

continual R-factor.  The insulation between studs may be

rated as an R-19 but the effective rate will be lower because

you have wood – insulation – wood, etc.  One way to improve

on this is to use a continuous insulated/structural board as

the exterior boxing.

The Building Envelope: Part 2


with Steve Medlin

ThermaSteel Installation


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