Ceiling Isolation

[Alex W]

I'm new so pardon any retreads. I've looked at the SAE site as well as several ongoing and previous threads but have few questions I can't yet figure out.

I've got a 600 sq. ft. outbuilding on my property with a roughly 20' x 20' open room that I want to convert into rehearsal space (I'll try and post some photos soon). Neighbor-proximity requires sound isolation for late night heavy bass-drum-and-guitar jams. Due to existing windows and sliding glass doors (two), I'm going with the room-inside-the-room concept. I understand the walls from previous posts and that should all be doable. Also, the windows will provide good AC duct outlets as recently proposed (very timely, incedentally).

I've stripped out the old carpeting a now have a concrete floor to work off. My thought is rubber strips beneath the wall footings and carpet once its all finished.

Biggest quandry is what to do about the ceiling. I'm redoing the drywall on the existing ceiling and plan to install it on resilient channel with insulation in a slightly pitched attic followed by a plywood and composition shingle roof. Is there any way that I can butt my new studio walls up against the finished ceiling and achieve an acceptable seal? I'd rather not build a secondary false ceiling in order to conserve the headroom I've got. Next choice would be to tie my new studio walls into the roof joists and split the drywall around them; but this would leave a 2-inch or so gap between the new and existing walls that may be troublesome to finish.

Thanks in advance--Alex

[John Sayers]

put a rubber seal between you new walls and the ceilng. Stop the drywall 1/2" from the top and use a flexible sealant to finsih off the gap. Sounds cool - will be a great rehearsal space. Oh BTW did you consider building your inside walls inside out like I did in Left Bank, it gives you acoustic treatment inside as well.


cheers
John

[Alex W]

Thanks John.

Yeah, I've taken a look at the left bank pictures and related diagrams. Thanks for forwarding additional graphics.

As luck would have it, your most recent diagrams have me a little confused. It appears in your reply post that you're attaching the insulation to the existing wall rather than the new wall. I'd gleaned from previous discussions that the insulation can be applied to the exterior side of the new wall. Probably doesn't make any difference but let me know if I'm off base.

[John Sayers]

It doesn't matter so long as the insulation is in the cavity between the walls.

cheers
John