House Buying Advice for Home Studio

Hi, I'm looking to buy a new house in the Toronto area, but within my price range there are no new homes (i.e no >10' ceilings). I'd really like to do a room-within-a-room, so I'm looking at costs to underpin, and to do that I need to know how far I'll need to dig down. I gather I can probably forgo a floating floor, if the basement is concrete slab. I gather I'll likely be okay with an 18" air gap between top of joist and top of the suspended ceiling. I'm guessing two-layers of drywall totaling 25mm should be enough? Cavity filled with glass-fiber of course. My main goal is to ensure that the piano, drums, acoustic bass won't wake up main floor occupants (wife and kids). Thanks, Dave

welcome! you're likely to be ok with just an 8" air gap assuming you beef up the upper floor mass and a proper amount of mass on the inner ceiling below.

Thanks for the reply! Is this what you mean by beefing up the mass (see attached)? If my walls are STC 63, it looks like the ceiling at <STC 56 will be the weak link by far. I say <STC 56 because the joists in this area are all 2x8, not 2x10. Increasing the air gap would help though I'll be short on headroom. Adding more mass I'm guessing is pointless (likely it's already at a point of diminishing returns). Any other convenient solution? As opposed to resilient channel (neoprene/rubber) I have seen some ceilings suspended by Neoprene+Spring Hangers (eg http://www.mason-uk.co.uk/pages/30N%20installed.pdf), would these give any useful added benefit in my situation? Thanks, David

the beefing up will help and using isolation clips and hat channel to support the ceiling will definitely be better than RC-2 or directly attaching it (or just using felt or neoprene strips). one option is to put more mass into the live room space where you have drums or loud amps and less in the CR where you're likely to limit the overall volume.

Thanks Glenn. My idea was to do as attached, with springs selected to give decent deflection (1" to 2"). Also, the drywall would be supported by a low-profile metal grid frame. It should (I hope) consume only a tiny bit more headroom than the RC construction. As I understand it, vibration isolation efficiency is related to static deflection (more deflection = more isolation, until you overload). With a spring you can obviously achieve much greater deflection than you can with rubber (RC), so should it perform a lot better? If so, any idea how much better? Would it justify the added cost versus RC? Best regards, David

the isolation brackets - spring or rubber - operate within a given range of weight to ensure best performance - usually somewhere around the 30-50% mark but most manufacturers will provide the movement range and weight which is optimal for a given product. going all out or not going enough results in less isolation for the lower frequencies. the RC-2 can be workable but the challenge is avoiding "shorts" when screws make contact with the underlying joists and there is a weight limit which then requires more RC and then (since its less efficient) you end up coupling more strongly. from a cost perspective, it's a matter of your isolation requirements versus what you can pay...