Cathedral Ceiling Insulation
Hello all,
So my wife and I are in the pricess of building a house/personal recording studio in Kent, Ohio. In the interest of making the building as energy efficient as possible it was built with 2×8 framing on the walls and 2×12 rafters over the “great room” with will also serve as a music recording space. So 2/3 of the house has trusses and a second floor but the final 1/3 is the great room. The rafters form a 12/12 roof pitch but there are additional supports attached to the trusses that will leave the ceiling once drywalled in a gambrel shape.
The exterior of the entire structure is covered with 2″ of Comfortboard mineral wool installed according to Roxul’s instillation guide and even with no internal insulation the building so far is remarkably temperature stable and very quite. For the walls I am planning on using mineral wool batts but I am looking for advice on the great room. Would a combination of mineral wool batts in between the rafters as well as blown in mineral wool above the drywall be advisable? The roof is non vented. Thanks so much!
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Replies
If you can add vent channels in that catherdral ceiling you'll have more options for insulation. For a non-vented catherdral ceiling, I would only personally trust closed cell spray foam. Non-vented cathedral ceilings are prone to severe moisture problems with most types of insulation. You'll absolutely want to avoid any type of penetrations in the ceiling drywall too (no recessed can lights!).
It sounds like you've already built your walls, but you might consider modifyting them slightly to turn them into a double stud wall, possible just adding staggered interior side studs. By using seperate interior and exterior studs, you decouple the two sides of the wall which does wonders for sound isolation. About the only thing better is a concrete wall (which is what the studio I worked in way back in the day had).
I'd consider hanging the walls around the room on the interior side on resilient channel if you don't want to do double stud walls all the way around. Use at least a double layer of 5/8" drywall too. All of this will help block sounds from outside your studio to keep things quiet. Commerically I've built 3 hour walls with 3 layers of 5/8" drywall on both sides, and those are very nearly as good as a concrete wall in terms of sound attenuation. The downside is walls built that way are VERY heavy, so you'll need to be careful with your framing to make sure you can support them if they're high walls.
Bill