Sound insulation of stud walls

[Richard C]

I’m forming a new en-suite with W/C using a 4” stud partition to an adjacent bedroom. I had previously read Part E but as it continually refers to new buildings or buildings with change of use I assumed it did not apply in my case, can anyone advise?

Assuming I have got it wrong & I will have to comply; I assume that standard, 12.5mm plasterboard on it’s own doesn’t meet the required 10km/m2 but what about with a 3mm plaster skim? I’ve already bought the PB & one side is already up, am I now going to have to double up on the thickness? On just on one side or both?

Also, with regard to the mineral wool infill, what actually meets the minimum density of 10kg/m3, min 25mm thick. I was going to use a load of 50mm Knauf cavity insulation bats I have left over (double thickness), anyone know if these would be suitable or do I need to use a specific sound insulation product; if so which one?

 

[^woody^]

Stud walls are normally filled with rockwool to provide sound insulation.

Even if not a particular requirement (part E conformity is not required in this case), then it's still good practice - especially for bedroom/bathroom/WC walls

 

[freddiemercurystwin]

It’s the board itself that needs to achieve 10kg/m2, not the overall density (board + skim). You'll need to add a 10mm layer to that side and use 12.5 soundbloc or 15mm fireline for the other side (whichevers cheapest). The insulation you've got is designed as thermal insulation and consequently they don’t publish the density (as they want you to buy their sound insulation instead). I've never used it as sound insulation (but then I work for architects and when I'm at work I cannot condone its use if the manufacturer does not recommend it) but it would probably be ok. If you’re getting approval you’ll probably not get away with it (depends how honest you are). If you need to use an alternative insulation you'll be able to pick up the right stuff in any builders merchant fairly cheaply, use 25mm Crown Acoustic Partition Roll (also Knauf) but they’ll probably have a few other choices.

 

[freddiemercurystwin]

(part E conformity is not required in this case)

If a new wall is to be built in an existing dwelling and is for a bedroom or wc then it does need to comply.

 

[^woody^]

[

If a new wall is to be built in an existing dwelling and is for a bedroom or wc then it does need to comply.

Can you provide a reference for that?

I'm not aware that this is controlled work

 

[freddiemercurystwin]

[

If a new wall is to be built in an existing dwelling and is for a bedroom or wc then it does need to comply.

Can you provide a reference for that?

I'm not aware that this is controlled work

I asked building control this very question not so long ago as I couldn’t find it in the regs myself and was directed to E2 in the green table on page 9 (of the PDF) http://www.planningportal.gov.uk/uploads/br/BR_PDF_ADE_2003.pdf

Interestingly it also states it here; http://www.planningportal.gov.uk/england/genpub/en/1115315234140.html

 

[Richard C]

[

If a new wall is to be built in an existing dwelling and is for a bedroom or wc then it does need to comply.

Can you provide a reference for that?

I'm not aware that this is controlled work

I asked building control this very question not so long ago as I couldn’t find it in the regs myself and was directed to E2 in the green table on page 9 (of the PDF) http://www.planningportal.gov.uk/uploads/br/BR_PDF_ADE_2003.pdf

Interestingly it also states it here; http://www.planningportal.gov.uk/england/genpub/en/1115315234140.html[/QUOTE]

I initially took the same view as woody & it’s exactly how I made the mistake of thinking I didn't need to comply; it was only after re-reading it several times I began to wonder, hence the post. As I commented recently, why the hell the ODPM technical team can’t write these specs. so they are simple to understand I really don’t understand!

Not being a lover of hollow stud walls I was always going to improve the sound insulation anyway, it’s just that I intended to use some left over cavity bats. Rather annoyingly, I was going to build the wall using 4” Thermalite blocks (which I already have) but went with the stud for quickness! It’s not a complete disaster as it’s only a couple of additional, 10mm boards on one side & a single Soundblock board & some proper insulation on the other; half the wall is to be boarded in Aquapanel (shower) & I’m assuming that more than meets the 10kg/m2 requirement can you guys confirm?

As always, thanks to all for the prompt response & info; oh & freddy, isn’t the green table on page 8?

 

[freddiemercurystwin]

Aquaboard is 15kg/m2 so that complies no probs. Its really up to you whether you bother with the proper insul or not and indeed the extra board, it depends if you have building control breathing down your neck or not, I'm just stating the facts! Its probably not gonna make a lot of difference tbh.

why the hell the ODPM technical team can’t write these specs. so they are simple to understand I really don’t understand!

You wanna take a look at Part L!

oh & freddy, isn’t the green table on page 8?

I meant page 9 of the pdf document as you scroll through.

 

[^woody^]

That planning portal reference is very misleading.

The reference to compliance with E2 and more generally with the Building Regulations, only applies when the work itself is controlled work - ie if the work is such that it is controlled work and thus notifiable to the LA then it must conform to the B/regs.

Therefore if you need to conform, then (unless exemptions exist) you also need to make a formal application to the council.

The erection of a partition wall is not controlled work, and therefore there is no requirement to apply for approval, and no requirement to meet the b/regs.

Remember that the Approved Documents are not the Building Regulations, they are just an approved way of complying with them

 

[Richard C]

That planning portal reference is very misleading.

The reference to compliance with E2 and more generally with the Building Regulations, only applies when the work itself is controlled work - ie if the work is such that it is controlled work and thus notifiable to the LA then it must conform to the B/regs.

Therefore if you need to conform, then (unless exemptions exist) you also need to make a formal application to the council.

The erection of a partition wall is not controlled work, and therefore there is no requirement to apply for approval, and no requirement to meet the b/regs.

Remember that the Approved Documents are not the Building Regulations, they are just an approved way of complying with them

The new en-suite is just a part of a whole host of other stuff I'm doing here & is subject to on-going BC inspection visits; there is also a new soil stack, electrics, drainage etc. so I will have the nice inspector around for tea & cake fairly soon! Although I think the extra work won't make any difference in practice, it's not going to be worth the hassle; I might as well just comply!

 

[londonman]

Now I'm totally confused!

I'm renovating an old property under Building Control notice. It's an old oak framed timber building. I've taken down all the old internal lath and plaster walls leaving behind the open oak frame that will form the wall between rooms. Some of this oak frame I will leave exposed. So what to put in the gap ? Some I was going to simply put some Kingspan and then plaster skimmed. Other gaps will be plasterboarded and skimmed. So do I have to rethink everything now because of sound insulation regs? I'd rather not.

I was also proposing to divide up some of the larger areas using stud partitioning and simply putting 12mm plasterboard on each side with nothing in the gap. Is this now wrong and I have to put sound insulation in between the plasterboard because of the Regs ? Again, I'd rather not.

Having read and re-read this thread I'm not sure

 

[^woody^]

The erection of a partition wall is not controlled work, and therefore there is no requirement to apply for approval, and no requirement to meet the b/regs.

 

[londonman]

Hi Woody...yes, I did read that but then saw the reply afterwards which seemed to suggest that BC did still need to be involved and as there was no further disclaimer......... and so thanks for the clarification.

What about the existing internal oak frame where I've knocked out the old infill panels. Are they exempt as well?

 

[^woody^]

This would seem to be maintenance, and as such you are not obligated to conform to any b/regs.

It would be optional, but perhaps wise to take the oportunity to make the walls as thermally and acousticallly efficient as possible - subject to budget.

For the proposed internal partitions, no need to inslulate unless you want to - would there be an advantage to?

But I'm assuming these partitions are not to make any other habitable rooms. If you are say making a new bedroom, then this operation in itself (as opposed to just constructing the partitions) would require b/regs approval and other considerations come into play - means of escape and electics come to mind

 

[londonman]

Mmmm..depends what you mean by making a new bedroom. Do you mean as part of a new extension. If so then I understand.

But I am dividing up a large area into a couple of bedrooms where previously there was only the one and a large wasted space in the landing area.

I've had the discussion with BC regarding the windows etc and they did try and get me to replace them with those 'orrible ones that swing open from the top but I did know enough about the regs to reason with him that what he was saying only aplied to new builds and I was replacing like for like.

Likewise electrics...BC will inspect at first fix.

Thermal insulation going in everywhere as per regs.

So sounds like (no pun intended) that I don't need to worry about mandatory sound insulation.