Gutex VS Rockwool
Northof60
| Posted in General Questions on
I was wondering if anyone had real world experience with the use of Gutex vs Rockwool comfortboard 80?
The price of Gutex is slightly higher, but I think it may be quicker and easier to use? Any thoughts?
I’m looking to put 6” on the exterior of our new home build in climate 7a
-1/2” GWB
– 2×3 service cavity with insulation
-6mm poly ( can’t justify a 4000$ smart vapour barrier in a cold climate)
-2×6 interior wall with insulation
-3/4” plywood sheathing
-6” continuous insulation
-vertical rain-screen (1×4)
-horizontal strapping (1×4)
-lightweight metal board and batten siding
Any and all thoughts or suggestions are welcomed.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Search and download construction details
Replies
I haven't personally installed either of them on projects but I have talked about it in depth with many builders and I can't think of one who doesn't find Gutex (or Steico, its main competitor, pending TimberHP's product launch) to be not just easier than mineral wool but easier than foam as well; the typical tongue-and-groove edges lock together and don't need to land over studs, and it seems to be more compression-resistant than the foam boards typically used on walls.
Your wall assembly sounds good to me. According to building science and the IRC, you shouldn't need the poly; with that interior/exterior insulation ratio, just painted drywall is enough of a vapor retarder. But Canadian code and some US state codes still require a membrane.
Thanks for the reply Mike. Where can I find more info on needing or not needing a class 1 vapour barrier?
Northof60, this is a good overview: https://www.greenbuildingadvisor.com/article/continuous-insulation-part-1, or hundreds of questions asked in this forum in recent years.
Michael,
A small point but Canadian building codes call for an interior vapour-barrier, but allow that to be any material that meets the criteria of being less than 1.0 perm.
Malcolm, thank you for the clarification.
Check out Membrane which is a lot cheaper than Intello etc. It is a vapor retarder rather than a vapor barrier. My experience, also second hand from my builders is that Gutex is considerable easier and quicker. The main thing with any wall/roof system is identifying the primary air barrier and detailing it so that it doesn't end up full of nail holes.
Summary, Rockwool compresses and post #22 makes a pretty compelling case.
https://www.greenbuildingadvisor.com/question/rock-wool-vs-wood-fiber