Soundproof/Waterproof Bathroom Stud Wall

[Possom]

I’m not sure if this is the best forum on the site, though the question relates to waterproofing…

I want to have a bathroom stud wall soundproofed (to prevent sound penetration from shower through stud wall), and also have the same wall waterproofed against water falling on it from both an overhead and a wall mounted shower, I was thinking of doing the following:

a) Insert Rockwool 50mm acoustic slab within stud

b) Screw 12.5mm Gyproc Soundbloc plasterboard onto wall

c) Screw 9.5mm Gyproc standard plasterboard on top

d) Adhere Homelux wall matting onto this, with Homelux tape for joints

e) Apply tiles

The two different thicknesses of plasterboard helps break up the sound wave.

I was speaking with a plumber, though we hadn’t been talking about the acoustic reduction part, just the waterproofing.

With regards to the waterproofing, he said he screws 0.5 inch Chinese plywood directly onto the stud. Onto this he paints some sort of tanking product, I’m not entirely sure what this is but could find out. Then tiles are adhered directly onto this.

Which method do you think is better with regards to the waterproofing?

 

[SFK]

Posson,
For the waterproofing/tiling, do not use Plyboard.
Where the shower is, rather than plasterboard use an Aquapanel Water-Resistant-Wall-Board such as this (which is basically a concrete board that does not get damaged when it gets wet),
http://www.wickes.co.uk/Knauf-Aquapanel-Water-Resistant-Wall-Board-1200-x-900-x-12-5mm/p/207027
which is then Painted with a Tanking / Waterproofing kit as suggested by your plumber (or your Homelux wall matting) that then makes it waterproof such as this:
http://www.screwfix.com/p/mapei-sho...gclsrc=aw.ds&dclid=CJ-GyYHcrtYCFa6m7QodnP0G6A
or
https://www.google.co.uk/search?q=b...-ab&gfe_rd=cr&dcr=0&ei=e72_WYemNIvH8Afg26GgCQ
And then tiled.

Note that the Water-Resistant-Wall-Board has a very high density (it is heavy) and is likely to absorb sound about as well as the Gyproc Soundbloc plasterboard.

Also, you might perfectly soundproof the wall, and then the sound goes through the bathroom door or the floor. So do not overspend on the walls if other areas are not as good.

SFK

 

[Possom]

Where the shower is, rather than plasterboard use an Aquapanel Water-Resistant-Wall-Board such as this (which is basically a concrete board that does not get damaged when it gets wet),
http://www.wickes.co.uk/Knauf-Aquapanel-Water-Resistant-Wall-Board-1200-x-900-x-12-5mm/p/207027

Thanks very much for the links SFK.

Is the Aquapanel product something similar to Hardiebacker?

 

[SFK]

Possom,
My pleasure.
As I have never used Hardiebacker, I cannot be 100% sure, but as Hardiebacker is defined as a "cement backing board" then yes I believe it is the same:
https://www.travisperkins.co.uk/Har...MIhvCwkoiv1gIVSYuyCh3JeQRDEAQYAiABEgLqofD_BwE


Nice photos here showing why best not to use normal plasterboard behind shower:
https://www.diynot.com/diy/threads/...tuck-last-owners-efforts.488058/#post-3979676
SFK

 

[John506]

Seems like overkill, have you considered ear plugs?

 

[Possom]

Seems like overkill

I believe the same technique can be used in double glazing where the intention is to reduce sound penetration through the window.

That is, each of the two panes is a different thickness.

 

[John506]

Aye but the gap between the 2 panes of glass plays a very important role too.

Just can't see it making much more difference to just standard moisture board and tiled.

 

[white_noise]

I believe the same technique can be used in double glazing where the intention is to reduce sound penetration through the window.

That is, each of the two panes is a different thickness.

Having to panes the same thickness causes a resonance known as a coincidence dip towards the higher frequencies, the resonance allows more sound to be transmitted through the glazing at this frequency dip.

In regards to the partition wall above having two layers of different thickness board on the same side of the partition doesn't break up the sound waves, all it does is increase the surface mass of that wall leaf. TBH it would be marginally better to just have two layers of 12.5mm Gyproc Soundbloc plasterboard, as this is more dense than standard plasterboard, and also thicker. Both of these things increase the surface mass of the wall leaf.

How thick is the cavity and what is the wall leaf on the other side of the stud wall?

 

[Possom]

How thick is the cavity and what is the wall leaf on the other side of the stud wall?

The stud wall is 7cm.

The other side of the stud wall is plaster on lath, so not plasterboard.

 

[Possom]

In regards to the partition wall above having two layers of different thickness board on the same side of the partition doesn't break up the sound waves, all it does is increase the surface mass of that wall leaf. TBH it would be marginally better to just have two layers of 12.5mm Gyproc Soundbloc plasterboard, as this is more dense than standard plasterboard, and also thicker. Both of these things increase the surface mass of the wall leaf.

Is the negative of increasing the surface mass of the wall leaf the fact that the timbers have to carry this; that is, without it necessarily decreasing sound penetration?