Exterior continuous insulation in residential applications
Gentlemen,
Has anyone used the Roxul Comfortboard on any exterior applications on past projects. If so, has it improved on the performance of the exterior building envelope of the house? I was thinking of trying this application as I live in Alberta Canada.
Typical exterior wall
1. 8-1/4” hardy-plank lap siding
2. 2×4 wood furring @ 24” O/C
3. #12 heavy duty flathead coated rated screws
4. Roxhul Comfortboard with 6” in total thickness, overlapping joints to mitigate or reduce thermal bridging
5. Vapour permeable sheathing membrane
6. ½” Spruce plywood sheathing
7. Wood framing (2×6) @ 24” O/C w/ R-15 with Roxhul
8. 5/8” Gypsum drywall
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Replies
Aaron,
Q. "Has anyone used the Roxul Comfortboard on any exterior applications on past projects?"
A. Yes.
Q. "If so, has it improved on the performance of the exterior building envelope of the house?"
A. Yes.
For more information, see these three articles:
"Installing Roxul Mineral Wool on Exterior Walls"
"Wrapping an Older House with Rock Wool Insulation"
"Installing Mineral Wool Insulation Over Exterior Wall Sheathing"
Would filling your stud bay and decreasing the exterior insulation to 4" be better, easier and cheaper?
Brian,
Q. "Would filling your stud bay and decreasing the exterior insulation to 4 inches be better, easier and cheaper?"
A. Certainly better and easier. Not sure about cheaper.
Hi Martin,
Thanks for this information what you have posted for me. In your experience using a rainscreen and applying exterior and interior insulation such as Rockwool. What normally is the best thickness for exterior and inside the cavity to maximize efficiency for a single story 1500 sqft house - walls at 11' in height? Again, thankyou for your time.
Regards,
Aaron
Aaron,
I am currently installing 3" of Rockwool over Zip sheathing. We are using 2x4's for furring strips held in place by Fastermaster HeakLOK screws. The siding is Hardie Artisan with a 7" reveal. I am glad we are not installing 6" as things just get progressively harder and more expensive as you increase the depth. I am using 2x6" interior studs, and in my climate zone I was able to meet my desired insulation levels with the 3" of Roxul. You might find the linked presentation that discusses various wall assemblies in Northern Climates useful.
https://nnca.ca/sites/default/files/Optimal%20Wall%20Design%20for%20North%20Feb%2017-2016.pdf