Roof construction advice

[The_Fiddler]

Hi All,

Thanks for looking in!

I have a completely (Slab and building) isolated garage I am converting into a recording/mixing studio. Due to space restrictions, I have chosen to do a single room (I tend to record direct - Line 6/Roland V-Drums etc) so sound isolation isn't THAT much of an issue, not to mention I live backing onto a state forest strip on the down side of a dirt road with neighbours at least 30m away on the level side.

In saying that, if someone wanted to play acoustic drums at 1am and not piss the neighbours off, that would be grand (Remember I'm only asking about the roof isolation - everything else is MY problem!)

That aside - I've got a handle on HVAC, Wall isolation etc (Re: Gervais), however none of his roofing isolation methods make sense to my situation. Hence I'm here...

The roof at one side is 2390 and the other is 2440. Now this is from the bottom of the joists, which are 250 in size, and roughly 430 apart, with then a colourbond kliplok style roof above.

I just haven't found the best isolation method for the roof and would like some suggestions.

I was thinking a roof that was supported by the walls was probably the go and then putting insulation in the cavities for heat mainly, but some level of extra isolation would work. the other option I thought was to look at Resilient Channel suspension or even just some suspension of some description as per Gervais, but I'm sure someone has done this effectively before, hence the post.

Appreciation (And beer if you're local to Emerald) for any help.

Expected Room Dimensions (Internal AFTER Isolation) H 2300 W 3800 L 4630

Can grab some pics tomorrow if needed.

Cheers

Rod

[Soundman2020]

so sound isolation isn't THAT much of an issue,

Do you do any live recording with mics? Does it rain in Victoria? ( ) Does the wind blow? Hail? Thunder? Aircraft flying overhead? Cars passing on the road every now and then? Animal noises? Radios? TV? People talking outside? ... you might want to re-think your need for isolation...

I've got a handle on HVAC, Wall isolation etc (Re: Gervais), however none of his roofing isolation methods make sense to my situation. Hence I'm here...

If you understand wall isolation, then you also understand roof isolation. It's exactly the same. Just do it as a fully-decoupled two-leaf MSM system, and you are done. You need roughly the same surface density on the inner-leaf ceiling as you have for the inner-leaf walls, and ditto for the outer leaf. Of your current roof is no good for that, then you might need to go to a 3-leaf solution, which is a bit more complex but sometimes it's the only solution for roofing.

I was thinking a roof that was supported by the walls was probably the go and then putting insulation in the cavities for heat mainly,

In the case of isolation walls, the insulation is NOT there for heat; it is there for acoustic damping on the numerous resonances that are happening inside the wall cavity. Which is why the insulation has to be of the correct type (gas flow resistivity) and correct thickness.

but some level of extra isolation would work.

Insulation by itself does nothing to isolate. It works as part of the isolation system, yes, but by itself it provides about zero isolation.

the other option I thought was to look at Resilient Channel suspension or even just some suspension of some description

You can do your inner-leaf ceiling like that if you want, provided that you follow the same rules as for normal two-leaf construction.

In short, it makes no difference how you hang the ceilign: Either on it's own separate inner-leaf frame that sits only on the inner-leaf walls, or using clips/channel on the existing joists. As long as you keep everything properly decoupled, and have enough mass on each leaf, and enough air gap, and ensure that both leaves are fully sealed air-tight, then you will be OK. You would get a bit better isolation with a separate frame as compared to clips/channel, but if you don't need major isolation then clips/channel is an option.

Can grab some pics tomorrow if needed.

That would be good, yes!



- Stuart -