Fibre cement ceiling problem.

Hi all, my room measurments are, Width 4.7 mtrs, Length 8.1 and height is 2.8 mtrs going up to a 20 degree pitched ceiling so roughly 3.5 mtrs. The floor is concrete with 2 layers of plaster board on the walls, my studio is 60% complete so i wont bore you with the other details. The ceiling is 2 layers of fibre cement board and ive used this to help sound proofing only, and it sounded terrible after hitting my snare drum in there today. Can you give me an idea on what i could cover this surface with i was thinking a single layer of plywood. Please help, the plasterboard walls go up next week. Yours faithfully Mick.

What do you mean by fibre cement, is it fixed to the inner ceiling or is the roof actually made from it? and how thick is this stuff? Sounds similar to my problem with a corrugated asbestos roof. You'll need to get this sorted sooner or later as the most soundproof walls are a waste of effort if the roof will suck. Or are you talking about acoustics inside the room itself? Please give us more info, plans, materials and most important of all FRAMING PICS! :P

Hi Deluk, fibre cement is sheeting just like plasterboard exept much heavier because its made with cement and is also quite reflective. The sheets are 7mm thick and the same width and length as plasterboard or drywall, the ceiling is completey covered with 2 layers of fibre cement board then above that are the rafters with insulation with a 300mm air gap which continues down through all four walls, above the rafters there is another 3 layers of the fibre sheeting then the roof. Ive built the structure from scratch and it is seperate from my house, the outside walls are 140mm thick concrete blocks all core filled with concrete inside the inner cavity to help with sound proofing. You might say its overkill but its what i needed to do so my local council whould approve the studio along with an acoustic report that set me back $1000. The room specs are 8.1m x 4.7m x 2.8m the ceiling is pitched at 20 degrees so the height at the centre of the pitch is 3.5m the walls are plasterboard and the floor is concrete and no control room im a drummer so i need all the room space i could get. Sorry that i dont have pictures a digital camera wasnt in the budget gonna try borrow one today. Mick.

Sound like a great project, we'd all love to see some photos (plus if you are asking a question, a picture tells a thousand words :idea: ) Well I'm no expert, but it looks to me like your ceiling will be a big weak spot in your soundproofing. The walls seem to be perfect, 140mm concrete kicks butt, and then I presume theres an insulation filled airspace? ...and how many layers of plasterboard? I'm not sure that 14mm of any material is thick enough for a leaf, especially where drums are concerned. You probably shoulda gone with an inch of plasterboard instead. Incidentally, what is the outer roof made of? The whole kit will sound terrible if you haven't treated your room acoustically, the hits will bounce of the hard surfaces and cause all sorts of muddiness, you should definitely be thinking about some clouds on that ceiling. Cheers Deluks