Internal wall insulation?

[matthew123]

I'm having someone construct a 6 x 7 foot internal partition to fully split 1 room back into 2 (have to work with existing internal wall of 113mm) - and have decided to have a 2 x 3 softwood stud partition so I can have thicker plasterboards.

I want to put insulation in the cavity between the plasterboards to limit noise & heat loss. Insulation has to be less than 64mm thick (based on 2 x 3 frame) but no idea what is the best soltution, blocks, which blocks, something like rockwool etc? Anyone any advice?

[HonaloochieB]

Where's Barry Bucknell when you need him?

[HonaloochieB]

Just found out he died on 21st February 2003. So now we know where he is when you need him.

[copleston_charlie]

Use soundboard instead of plasterboard - thicker, denser plasterboard which helps with noise insulation, you can order it from travis perkins IIRC. You can then get pads of insulation which are denser than the looser 'default' insultation you'll find at B & Q. I think it might still be fibreglass/rockwool but it's easier to cut and fit into a void in the partition. You might be able to wedge in two layers on top of each other. I did this in my last house and seemed to work fine, but I have no idea how this does/doesn't fit building regs ;-)

[red devil]

Rockwool Flexi...

Rockwool Flexi comes in variable thicknesses, studs should be at 400/600mm centres, self-supporting the insulation is simply wedged between the studs, don't use loose loft type insulation, over time it will just collapse into a heap at the bottom. Use a mastic seal/decorators caulk at plasterboard junctions with wall and floor to seal any gaps. Also run a mastic seal under the new skirting board, this will also prevent the dark stains that appear at the edge of the carpet finish.

[SteveT]

HonaloochieB wrote:- Where's Barry Bucknell when you need him?

That makes you a senior on this forum HB but it takes me right back to my misspent youth.

They've only heard of Tommy Walsh round here HB.

[matthew123]

cheers guys

How would "dark stains" occur ?

I'm now thinking I'll construct the partition wall myself (then get a pro in for the plastering) - assuming I go with the Rockwool Flexi and Soundboards (plus softwood), anyone know which is the best place for price and delivery for a mere retail customer?

[red devil]

Try Travis Perkins Matthew, there is a branch behind the Old Kent Road before you get to B&Q.

It might be worth your while getting a plasterer lined up first, and strike a deal with him that you'll give him the job if he can get these materials at trade price for you, cheeky but worth a punt.

The 'dark stains' are common in older properties, behind the skirtings there is usually bare brickwork and over time soot and dust collects, eventually working it's way under the gap between skirting and floorboards. Dust can also come up from the floor void through the gaps in the floorboards. If you are building an internal partition probably less of a concern but still worth doing as it will help with acoustics...

[matthew123]

cool

one other concern is I want to put in some electric sockets on both sides of the partition wall - but to avoid the flexi blocks pushing up against the electric wires (which may spark a fire according to rockwool customer services) what sort of thickness do you think I can go up to if my stud partition is 3x2 (i.e. 64mm gap)?

[HonaloochieB]

SteveT Wrote:

-------------------------------------------------------

> HonaloochieB wrote:- Where's Barry Bucknell when

> you need him?

>

>

> That makes you a senior on this forum HB but it

> takes me right back to my misspent youth.

>

> They've only heard of Tommy Walsh round here HB.

Tommy Walsh wouldn't be fit to hone Barry's second-best chisels.

OK for hunping paving slabs about, but ask him to construct a box using mortis and tenon joints and he'd befoul his shorts, like as not.

[iaineasy]

hey if your looking to have your partition skimmed I could do it in a day for ?120 plus materials!

drop me a pm or give me a bell if you like 07984336300

]hugs

Iain

[woofmarkthedog]

Build the partition as stated but fill the void once built with expanding foam, available at Build centre in Dulwich in a can it's a little more expensive ( rockwall has very little sound proof quality anyway ) but would seal & insulate an area that size well.

The best Plasterer in the business is Kevin 07973-633694 he charges a day rate which usually includes material ?170 a day-ish but worth his weight in gold.

W**F

Plus if you are doing the work your self use dry wall screws to fix the board & make sure the heads are in , do also make sure the plasterboard is the right way round for skimming.

[red devil]

matthew123 Wrote:

-------------------------------------------------------

> cool

>

> one other concern is I want to put in some

> electric sockets on both sides of the partition

> wall - but to avoid the flexi blocks pushing up

> against the electric wires (which may spark a fire

> according to rockwool customer services) what sort

> of thickness do you think I can go up to if my

> stud partition is 3x2 (i.e. 64mm gap)?

Not sure what Rockwool are on about Matthew, this is standard construction detailing. Assuming you want low level power sockets i.e. just above skirting height, the electrical cables are normally fed from underneath the floor void and directly through the bottom of the wall and into what is known as a back box. The wires are connected to the plug terminals inside this back box, and once the wall is plastered a face plate with plug holes is fitted over the back box. The insulation is just cut around the back box, so shouldn't come into contact with electric wires. If you are having new electrics you will need to get a Part P certified electrician to do the work and sign it off, ask them about what Rockwool said...

[Jack Kelly]

If you're worried about your mains cabling coming into contact with the insulation (and hence overheating) then I think one option is to over-specify the cable... i.e. use thicker cable than you'd normally use. The larger the cross-sectional area of the conductor, the lower the temperature increase for a given current. So a big, fat cable will heat up less than a thinner cable, for a given current.

But yes, as Red Devil said, definitely check the most recent Part P regs. I think they're available for free online as a PDF download. I'm not a qualified electrician so please don't take my advice without checking first!