sound insulation

We're in the midst of planning a renovation (adding a new storey) and I keep thinking of possible problems that I have no experience to fall back on.

The inlaws have a McMansion in which I notice the walls offer little in the way of sound insulation between rooms. Is this always the way with timber framed construction? Searching on various sites, I see people talking about insulation for home theatres but what about normal bedrooms etc. Is there any point in looking at, say, Gyprock Soundchek level 1 + CSR Bradford SoundScreen? Using the calculator at
http://www.gyprock.com.au/tools/gyprock/calculator.asp the cost of materials for 75sqm of wall is $390 (standard gyprock) vs $1100 for the other stuff I mention.

Would the SoundChek gyprock on its own make any appreciable difference vs normal gyprock?

Anyone have an opionion?

Tony, I've used http://http://www.spec-net.com.au/company/insol.htm before, formally known as ACI noise stop board. Very effective but I don't know the present costs. Perhaps pink batts may be enough for your job.

Hi Tony,

A company in Sydney ( Thermotec Insulation ) makes a product called Soundlag 4525 which comes in a roll. This product is mainly used in commercial applications for controlling water noise in stack pipes of multi story buildings. It could be used in walls I suppose but a call to them may put you in the right path.

Soundlag has also been used for recording studios. It's a foam "eggshell" type of product that may be of some beneift.

Cheers

Pat

Hi again Tony,

Here's a link to Thermotec Nu-Wave sound insulation.

http://www.thermotec.com.au/acoustic.htm

Hope this helps

Pat

I have recently used the CSR soundscreen and found their website useful. It costs a bit more than normal batts but in total they are a small part of a project cost.
I would also recommend you contact CSIRO Sydney if you have any special queries, they have a special division handling noise reduction.

You need to think about whether impact or transmitted sound will be the problem. Impact sound needs isolation mounts to prevent transmission of vibration. You could also use staggered studs. Transmitted sound needs a more dense wall. 10mm plasterboard does not offer much protection. Try using 13mm with a second layer of villaboard over the top. Also use insulation and seal around the plasterboard (eg underneath, behind the skirts) withgap filler. This prevents flanking noise.

Cheers
Pulse

Thanks for the replies. I called the ecopink people (http://www.spec-net.com.au/company/insol.htm) and spoke to a very helpful guy who gave what sounded like good advice for me (without rock guitarist teenagers, but wanting to improve sound insulation)

1. Sound insulation and thermal insulation require different products so don't expect one to do the other's job

2. Between floors, fill the cavity with their basic batts (about $12/sqm)

3. In wall cavity, use their basic batts (about $20/sqm inc labour)

4. Don't worry about getting special plasterboard

He had done this to his house and reckons the result is equivalent to brick walls.

Check out a product called rockwool also

Hi I would suggest you dont use rockwool as it is an iritant to a lot of people. I find it worse than glass wool Doug

Rockwool is extremely hard to work with, yes.. but if you can put up with the stuff it is the most efficient way to soundproof a wall.
Its also a fire retardant.

Althought it is far better than standard sheet, soundcheck is pat of a system and offers only marginal results when used without batt insulation, it's also far heavier to hang. For bedrooms standard recessed edge would be fine with accoustic insultation batts. If you want to improve on that other options to look at include standard on one side, sound check or a double layer of standard on the other side of the wall.

One thing that hasnt been mentioned is floor transmission in regards to floor coverings (second story). Dunlop sell an underlay thats specifically for second floors, and does a lot to reduce noise to downstairs - in conjunction with carpet of course. carpets will make the biggest difference - if you put tiles or boards upstairs, no amount of batts will help - vibration is mechanically connected to the lower floor ceiling.

All the above is relatively cheap to do during contruction, batts in walls (good themally as well), extra gyprock - 13mm as minimum, but before soundchek - I have used 9mm overlaid on 9mm (staggered joints and sealed) which worked pretty well I hear ;)