Install insulation into old walls ?

[bugsy]

I have old fibrous plaster and i am wanting to install noise reduction/ insulation batts inside them.
Mainly for the exterior walls.

I have been thinking of just pulling down the plaster of one wall and then re-plastering.
How will this go with the older plaster and is this viable anyway?

[rod@plasterbrok]

Unless the old fibrous plaster is in excellent condition you will be able to see a difference in the lining.

You may want to consider other methods like pump in insulation. I am no expert on how they do it. But I would think they could do the external walls without removing the plaster.

Just another thing, the noise control batts alone won't have a huge impact on noise reduction. If you just want to reduce traffic noise etc. then you will notice some difference. But if you a wanting to cut out the noise of a home theatre or other loud music, it will have little effect.

For loud sound reduction you need to consider other sound proofing methods.

Cheers Rod

[bugsy]

yes it is just for street noise.

thanks for your reply

[woodbe]

Old fibrous plaster is probably quite thick. If you do pull it down, make sure you replace with decent thick gyprock. You can get sound rated sheets, (pink, I think) we isolated a noisy A/C plant using 2 layers of sound rated gyprock and a full cavity of rockwool. Very effective. We used a lot of liquid nails to bond the sheets to the studs to minimise vibration.

The other trick is to eliminate airgaps in the outer walls - even a small hole allows a lot of sound in, it's easier to stop it there than fight it within the wall.

woodbe.

[rod@plasterbrok]

Just for you info,

You can achieve the same results as the sound proof board at half the cost. You can compare the effectivness and cost of every type of plasterboard on our site.

The manufacturers make a slighty denser product at vitually no extra cost to them, then flog it off at double the price. I had all the data on production cost of one of the major manufactures. (faxed to me by mistake)

Ceiling board that is $1.50 more than normal board, cost them 3 cents more per m2 to produce.

I am not a fan of sound proof plasterboard for this very reason. Other cheaper products work better.

There are 3 things to consider with sound proofing, density, transmission, and absorbtion. The sound proof plaster provides one of these, density. Insulation provides absorbtion. Rubber mounted isolation clips, and wall cavities provide protection for transmission.

Honestly, I cringe when I see people sold on using sound proof plasterboard. Even more when they want to use it in a manner or place where it virtually has no benefit at all.

Cheers

P.S Sorry about the gripe, just cant stand that product.