Internal wall make up - what’s best?

[Weebles]

Hi. Our plumber is first fixing our MBC timber frame build. Some box outs are needed and it got me thinking about walls.  I have no idea on materials so help needed please. 

 

What should the internal wall make up be?

Plasterboard (what depth, any recommendations?) screwed to the stud walls (which currently look like the photo)? Or ply / OSB first? If so what sort and what depth?

different ply / plasterboard for bathrooms?

and what type of insulation would you put in the wall?

what about walls that have stuff that will hang off them (bathroom and kitchen units and TV)?

 

Thanks. Going to have a go at some of this ourselves......

 

 

 

 

[Moonshine]

Internal walls like this need to achieve a min Rw 40 dB sound reduction (ADE requirement E.2), the British Gypsum white book gives an minimum example to achieve this as 63 x 38mm studs, 65mm isover APR 1200, and 1 layer of 12.5mm wall board either side (system ref A026012), though there are other ways to skin a cat but that involves Soundbloc and no insulation. But at the end of the day, having privacy between rooms is needed, and you may want to go over the minimum.

 

Note however that the ADE requirement E.2 does not apply to internal walls that have a door, or on walls that separates an ensuite toilet from the bedroom it serves.

 

In areas where you want increased acoustic privacy fill the cavity width with mineral wool insulation, 12-24 kg/m3 density, but don't over fill and compress it, and put two layers of 15mm Soundbloc on either side.

 

I would only put a OSB board liner (probably 12mm ) between the stud and plasterboard where you are looking to hang fixtures such as sinks, cabinets, kitchens.

 

As for bathrooms you may need to go for moisture resistance plaster, and probably 9mm hardie baker or similar where it may get wet (e.g. showers).

 

[Simplysimon]

@Weebles, i am wondering why four separate studs rather than one long one and two butting up against. doubling up the p/board will also be more difficult due to the position of the studs at the junction as only one thickness of material. i appreciate it will stop some flanking sound transmittance but as they are still touching there will still be some.

[Russell griffiths]

Our last house had osb on all walls under the plasterboard, I intend to do the same on this one. 

Solid feel, easy to fix to, not a lot more cost in the grand scheme of things. 

[Weebles]

 

2 hours ago, Simplysimon said:

@Weebles, i am wondering why four separate studs rather than one long one and two butting up against. doubling up the p/board will also be more difficult due to the position of the studs at the junction as only one thickness of material. i appreciate it will stop some flanking sound transmittance but as they are still touching there will still be some.

 

The photo was just to show a sample of what the studs look like.  This just happens to be the junction of two rooms which are back to back and 2 cupboards on the near side.  So at this particular junction I guess we prioritise the rooms and then we can sort out the cupboards afterwards.  Most of the other studs don't have this issue.  I probably picked a bad photo.

 

1 hour ago, Russell griffiths said:

Our last house had osb on all walls under the plasterboard, I intend to do the same on this one. 

Solid feel, easy to fix to, not a lot more cost in the grand scheme of things. 

 

What depth OSB?  Plumbers saying OSB not so great to fix to, need to use a decent ply if we want to screw into it securely?

Got a load of OSB on site - was going to use that behind areas of boxing out as they won't ever see the light of day again.

[MikeGrahamT21]

I've never had any trouble fixing to OSB, maybe not as good as ply, but certainly not a problem

[Ferdinand]

I think OSB benefits from the correct type of screws, which are discussed elsewhere.

 

I think the Reisser ones work well.