Studio Building with cement sheeting please help!

gavinchan · Post by **gavinchan** » Mon Sep 08, 2003 2:46 pm

I am in the throws of building a home studio. Currently there is only the stud framing and Cement sheeting finished. Should I add another layer of cement sheeting? Please help!

P.S what a great forum, a total lifesaver!

knightfly · Post by **knightfly** » Thu Sep 11, 2003 4:12 am

Gavin, sorry for the delay in responding - it's been pretty hectic lately anywhere I turn.

I'm not familiar with the product you're using, unless it's the 4 x 8 version of Durock?

Anyway, if you're sound proofing you want MASS, and AIRTIGHT construction. Your pic shows something poking out a hole in the wall - right off, this is NOT good - whatever that is, it needs to be thoroughly sealed with acoustic rated caulk.

As far as layers, if you offset seams and put up a second layer of your cement board, you will see at least 6 dB better sound isolation than without - provided you seal everything properly. Just be sure, before you do that, that you can MATCH that performance in the roof/ceiling/doors - otherwise, save your money. Soundproofing goes to the "weakest link" theory - 4 foot thick concrete walls are useless if you forget to close the door.

Other than that, here's a link to most of the "rules" of sound proof walls, check it out and ask the other 49 questions it will probably bring up -

http://johnlsayers.com/phpBB2/viewtopic.php?t=598

Hope that helps... Steve

gavinchan · Post by **gavinchan** » Thu Sep 11, 2003 10:27 am

knightfly wrote:Gavin, sorry for the delay in responding - it's been pretty hectic lately anywhere I turn.

I'm not familiar with the product you're using, unless it's the 4 x 8 version of Durock?

That's OK, I have been exactly the same, and thanks for your advice. The Product is called "Duratex" its a 7.5mm "Blue board" cement sheet. on 90mm wood studs.

knightfly wrote: Anyway, if you're sound proofing you want MASS, and AIRTIGHT construction. Your pic shows something poking out a hole in the wall - right off, this is NOT good - whatever that is, it needs to be thoroughly sealed with acoustic rated caulk.

I Totally Agree, I will do that.

knightfly wrote: As far as layers, if you offset seams and put up a second layer of your cement board, you will see at least 6 dB better sound isolation than without - provided you seal everything properly. Just be sure, before you do that, that you can MATCH that performance in the roof/ceiling/doors - otherwise, save your money. Soundproofing goes to the "weakest link" theory - 4 foot thick concrete walls are useless if you forget to close the door.

Thanks, that's good advice. I have solid core doors. The ceiling is an aluminium tin kind of thing. It has been lined with that ceiling stuff (foil on one side, and insulation on the other) , that's probably not that great is it?..... I will post some photo's this arvo...

knightfly wrote:Other than that, here's a link to most of the "rules" of sound proof walls, check it out and ask the other 49 questions it will probably bring up -
http://johnlsayers.com/phpBB2/viewtopic.php?t=598
Hope that helps... Steve

Thanks, I have just read through it 'phew!'. How should I attach the second layer of cement sheet? From what I read in the above posts, zero penetrations is best, so I am assuming that I should use some kind of construction adheasive only, and no nails/screws. Would this be right?

knightfly · Post by **knightfly** » Fri Sep 12, 2003 1:26 am

"How should I attach the second layer of cement sheet? From what I read in the above posts, zero penetrations is best, so I am assuming that I should use some kind of construction adheasive only, and no nails/screws. Would this be right? " -

Gavin, I'm not familiar with the "blue board", but 7.5mm is really thin for wall construction - you might need to see if you can find some "laminating" screws (the kind US Gypsum calls Type G, but I don't think they would work very well. Cement board usually takes its own type of screws, so I'm not sure how well gypsum screws would work.

Is this stuff normally used as you did? It sure seems flimsy for an outer wall - do you by any chance have a link so I can learn more about it?

Gonna hit the pillow for some rest, maybe I can think afterward... Steve

gavinchan · Post by **gavinchan** » Fri Sep 12, 2003 8:11 am

Here's a pic of my ceiling (so far)

knightfly · Post by **knightfly** » Sat Sep 13, 2003 9:57 am

Thanks, Gavin - now I need the answers to my previous questions before we can figure things out for you - please DON'T build anything else til we do, it could be a BIG mistake... Steve

gavinchan · Post by **gavinchan** » Mon Sep 15, 2003 9:17 am

Here is the link for the product used for the external walls.

http://www.bgc.com.au/fibrecement/

Click on "Duratex".

knightfly · Post by **knightfly** » Mon Sep 15, 2003 3:01 pm

OK, downloaded the PDF for this stuff - now I need to know how YOU built with it. Their site shows construction using fire rated gypsum wallboard UNDER the cement board, which explains the thin sheets working at all. IS that what you did? Please describe your ENTIRE wall construction from outside to inside, as it stands right now.

On your ceiling, are those 2x8 joists on 600 mm centers, or what?

After you detail ALL your existing construction, we can figure out what you need and how to get there... Steve

Post by **John Sayers** » Mon Sep 15, 2003 9:10 pm

On your ceiling, are those 2x8 joists on 600 mm centers, or what?

I love it

:D......... an American sneaking in metric references.

;)

cheers
john

knightfly · Post by **knightfly** » Tue Sep 16, 2003 2:18 am

Not quite, John - I still didn't call them "8 x 2's"