From The Build Show.
Let’s talk wall assemblies. Bomber wall options to frame a REALLY good wall with 2×4-6-8’s and some thick insulation. A home built with any of these 5 walls will be a comfortable, durable, efficient house that will last for generations. In this video I’ll run you through all the options, including the Costs!
6. 2×6 w/ zip R-3 (or R-6, R-9, R-12) and batt Rockwool R-23 insulation
* Effective R-value of opaque assembly = 22
* $3.62 per sqft
7. 2×6 w/ plywood, Delta Vent SA, Rockwool Exterior comfortboard 80 (1.5”), and batt Rockwool R-23 insulation
* Effective R-value of opaque assembly = 25
* $5.82 per sqft – (60% more than previous assembly)
8. 2×4 w/zip sheathing, Atlas energy guard 2” polyiso (R-13), and batt rockwool R-15
* Effective R-value of opaque assembly = 27
* $ 4.05 per sqft – (30% less than previous assembly)
9. 2×8 w/ zip R-6 (or R-6, R-9, R-12) and batt Rockwool R-30 insulation
* Effective R-value of opaque assembly = 30
* $4.82 per sqft – (19% more than previous assembly)
10. 2×8 w/ plywood, Prosoco R-guard, 3” of Polyiso (2 @ 1.5”, offset seams), and batt Rockwool R-30 Insulation
* Effective R-value of opaque assembly = 45
* $7.13 per sqft – (48% more than previous assembly)
R-value (effective vs nominal), pros, cons, price breakdown
Assembly R-value Calculator
* Prices only reflect lumber, insulation, WRB, and Sheathing of assemblies from my local lumber yard. Does not include hardware, fasteners, tapes, flashings, labor, etc. Used a 8’ x 8’ wall assembly to calculate.
* As you upgrade your wall assembly materials and methods, it is just as important to upgrade any other parts of the assembly that affect the performance such as windows and doors. This is just a look at the framing, sheathing, and WRB assemblies relating to R-values
All areas in the building envelope, except fenestration and building service openings such as vents and grilles.
A measure (h ft2 °F/Btu) of thermal resistance, or how well a material or series of materials resists the flow of heat. The R-value is the reciprocal of the U-factor.
Effective vs nominal r-value
Nominal R-value took into account the thermal resistance of the insulation layer only, typically batt insulation placed between the studs. Effective R-value, on the other hand, takes into account the cumulative value of thermal resistance for all materials within the assembly.
Renderings done by:
Lou Varni – @Lvarni
Huge thanks to our Show sponsors Polywall, Huber, Dorken Delta, Prosoco, Rockwool & Viewrail for helping to make these videos possible! These are all trusted companies that Matt has worked with for years and trusts their products in the homes he builds. We would highly encourage you to check out their websites for more info.