ceiling isolation

Aloha studio masters, I appreciate this forum and have learned much from this site during the last year. This is my first post as I have completed the shell of a structure that will soon be my personal recording space. I hope I don't step on any toes if I ask a very specific question without including all the details of my space and future plans. I live in an isolated area (gravel road) and rain on my metal roof will be the main concern as far as isolation goes (75 inches/year). My dilema is that I want T&G cedar or pine on the interior ceiling but I also need the isolation of 5/8" drywall with hat channel. I can't conceive of an effective means of acheiving isolation without a drop ceiling (which is not possible due to windows that are close to the finish ceiling). My gut tells me to do two layers of 5/8 and then the T&G but I'd have to nail through the drywall to secure the T&G to the rafters, thus ruining the isolation. Does anyone have any insight. I don't need total isolation; just marginal.

moose - does your metal roof sit on insulation above the battens??

Thanks for the reply John, unfortunately, no it doesn't. It is standard 2x12 rafters, 1/2 plywood, tar paper and then the metal. Any ideas. Thanks again

What would be the effect of applying plywood over the >top< of the joists? I envision that you must have little room to access the "attic" but couldn't it be plausible to erect a sheathed area using the joist topside that would minimize the rain ping effect to some extent? Maybe a sheathed with plywood sheetrock sandwiched type of configuration I do not believe this will create any type of negative "leaf" situation but I have been corrected before. In effect it would be like having a "better built wall" only it would be overhead. What do you think? Brien

Thanks Brien, The only problem is that there is no attic. It is a vaulted ceiling.

But it reads like it has not had any material installed as of yet? Could you not build panels with a ledger strip on either side that would allow you to attach the panel in the cavity in-between the joists...affixed towards the upper part of the joist? How 'bout this. Knowing nothing about the dimensions of this room, would you be able to build a system of light-weight "trusses", layed out and designed only to support the wood ceiling? Brien

Moose - removing the iron isn't hard, just unscrew it, lay insulation over the area and put the iron back on. That will significantly improve the rain noise. If you then add an RC mounted ceiling to the underside of your joists as you suggested and you should be OK. Green glue between the 5/8" sheets is another option to consider. cheers john

Brien, unfortunately the space at the top side of the rafters is reserved for much needed ventilation. In addition, there is very little room for trusses (drop ceiling) due to some rake windows which are very close to the finish ceiling. John, the insulation is a great idea that i wish I had thought of previously. This is not an option now since the roof is a snaplock system (which is expensive and easily damaged during removal). In addition I would have to remove and reposition all of the gable trim and gutter system. Tell me this, would I acheive a reasonable return on effort if I were to install 2 layers of 5/8" with greenglue inbetween followed by 3/4" T&G pine or cedar finish nailed through the sheetrock and into the rafters. Would the 16 ga. finish nails (very small gun nails) destroy the isolation since they are penetrating into the rafters. Do I have to give up on the notion of having it all ( isolation and the beauty/acoustic properties of a wood ceiling). only recording drums on non-rainy nights is an option (there will also be a small iso booth for other things). Last question: would finish gun nails penetrate hat channel? I think not but i've never worked with it before. I do appreciate all the assistance, Moose

Moose - you could probably glue 1/2" T&G pine to the drywall ceiling. cheers John

John, Thanks for the idea. I like it. Any tips on type of adhesive?

liquid nails.

thank you so much. This site is an unsurpassed resource. Cheers to you, Moose