trying to avoid a tripple leaf sysyem...

hi all, i am building a studio in an old building behind my house. the studio will have a life-room, a control room and two boots. everything will be built as described in rod gervais book "home recording studio - build it like the pro's" right now i am thinking of the best way to "fix" my roof. for the moment the roof is a thin layer of eternit. thats a building material often used here in belgium. its thin plate with waves in it (?) i dont know the name in english so thats the best way to describe it. it is absolutely NOT good for soundproofing. actually its just enough to keep the rain out... ;) my budget doesnt allow me to put a new roof on it so i'll have to "fix" it. the first drawing is the minimum. it is the roof - untreated - and the ceiling of my inner room. the second one is the easiest solution. but i am afraid to create a tripple leaf system like this. or maybe the existing roof is negligible as a leaf??? the third one is what i think is the best solution. it will surely be more work... but will it be better?? maybe someone knows of a better solution? any help is very appreciated. arjan

the third one is indeed the best solution. make sure the structure allows for added mass according to the building code or you might have a serious problem. Sounds like the existing roof is light so perhaps the studs holding it doesn't allow that much more. a :arrow:

the studs are strong enough. they are 12cm high and 6cm thick. but am i not creating little cavities between the drywall and the waves of the upper plate? would the second drawing give problems? it shure would be easier to install...

What's the eternit made from? is it metalic? or of a fiber composite? Are you sure about durability with leaks? On the third example you're providing the largest amount of space between the first leaf and the second. Although you would have a bit of space created in the ribbon pattern of the roof, you have more material (insulation & space) to soften the frequencies before they get knocked down by the second layer. Plus - think of maintanence: Let's say you went through the effort to fill the gaps between the mass and the eternit. Something that formed to the bottom of the eternit or was pressed up against it - It would likely be problematic if you had to replace a section of it.

As mentioned, the 3rd drawing is indeed the best solution to my amateur eyes. The middle drawing sure looks like a triple leaf setup to me. It is not easy putting drywall between studs like that, but folks around here do it all the time, and the process is described pretty well in Rod's book. (You do have Rod's book, right?) "Home Recording Studio Build it Like the Pros" By Rod Gervais ISBN: 1-59863-034-2 [url=http://www.amazon.com/Home-Recording-Studio-Build-Like/dp/1598630342/ref=pd_bbs_sr_1?ie=UTF8&s=books&qid=1202654599&sr=8-1]Amazon Link for Rod's book [/url]

here is a pic of the roof. the studs are actally 18x6cm and the distance between them is 90cm. the eternit is a fibre-like plate. it is made of a mixture of cement and asbest fibres :? it is 3 to 4 milimeters thick and when it rains it sounds like a giant snare roll... right now there are 3 or 4 places where i do have some water dripping in, but i'm gonna fix them first. it's easy to see if there was some leakage after rain cause it makes dark spots on the floor...