Insulating utility room

[Jimk]

MS polymer - Stixall, sika flex (I think), others are available...

[Jimk]

Sounds like a lot of farting about whilst introducing cold bridges & vapour channels into the previously contiguous insulation ....

Then affix plasterboard to

Polystyrene? The ones linked to & the only ones worth bothering with are PIR foam...

[Jimk]

There's always expanding foam made for fixing plasterboards?

[Paul Giverin]

About 25 years ago we had a small utility room built on to our kitchen. Its only about 1.5m x 1.5m internally and two of the four walls are part of the existing house, i.e cavity brick/block. The other two walls are single brick exposed to the elements. All the walls are bare brick internally. Nothing has been plastered. It has always suffered from some condensation on the single brick walls but this year we splashed out and replaced the original single glazed door and window with efficient sealed units.

With the onset of colder weather, the condensation seems to have got worse. I was thinking about tanking/insulating the inside of the single brick walls. When you take away the window and the door, there is only 3 or 4 square meters of single brickwork. I was considering simply attaching some insulated plasterboard (link below) to the internal single brickwork using a grab adhesive. Will this plan work?

Thanks

[Adrian Brentnall]

That's what that plasterboard is designed for (I used to work for the company that made it, back in the '70s. You'll lose a small amount of space from the room - but it will make the walls warmer. Using the tapered-edge board you can achieve a fairly neat / invisible join between the boards - there's a tape that goes into the taper before you apply the filler, to prevent cracks later.

[Paul Giverin]

Thanks for that. To be honest, I'm not too worried about how good it looks. Its only a utility room for appliances and currently is painted brick. I'll probably just be painting the plasterboard in the same colour as the rest of the room. I was just worried about the grab adhesive being up to the job.

[Tricky Dicky]

On the internal walls dry-lining as you suggest is not a problem but on the single brick exterior walls you would have to be sure there was no damp penetration from the outside. Tanking is perhaps one solution but I do not know how well various dry-lining adhesives will work with that all I know is that you cannot use mechanical fixings that pierce the tanking. I believe when converting cellars into living space the walls are lined with plasterboard on studding not fixed to the tanked walls, this of course reduces your floor space but does allow for insulation and fitting a vapour barrier.

Richard

[The Natural Philosopher]

yes. Perfect

[The Natural Philosopher]

Wrong. The plasterboard contains a vapour barrier. It is designed for this.

[Muddymike]

Ive just finished doing exactly that in one of our rooms. Its a recognised method for insulating solid walls.

Mike

[Andrew]

Alternatively, do as I did to the lounge and bedroom walls facing North. Use 30mm 'celotex' cut to the exact height of the room and fix to the wall using battens cut down from cls timber. This gives three battens 30mm thick. Fix these horizontally using

80mm frame anchors, then infill between the battens with more 30mm 'celotex' (I used Quinntherm). Then affix plasterboard to the battens, scim if needed or use tapered PB with glassfibre reinforcing.

There are foaming PU adhesives for fixing plasterboard, but you need to check that it doesn't disolve the extruded polystyrene on the back of the plasterboard.

[Andrew]

Only some variants do, intended for upstairs ceilings.

Most PB is not water vapour impermeable.

As long as there is a DPC in the wall, I would seal the outside with breathable water repellent sealant intended for this purpose.

[Paul Giverin]

Thanks to everyone for their input...... much appreciated.

I'm 99.9% sure that I don't have a problem with damp permeating from outside. It is all condensation forming on the cold brick walls. I think I am going to go ahead with using the insulated plasterboard. My only concern now is getting the best adhesive to bond the PIR foam to the brickwork. Given that the brickwork isn't dead even, I would like to use some sort of fill adhesive. Any suggestions for a grab/fill adhesive that is compatible with the PIR foam backing board?

Thanks.

[Fredxx]

That's expensive stuff but I guess easier to apply than battens and polystyrene infill between battens.

One concern using grab adhesive is how well it works with a wet wall.

[Mike Clarke]

Plain plasterboard may not be but any decent insulated board does have a vapour barrier.

[The Natural Philosopher]

Plasterboad with insulation is as all celotex/kingspan is foiled.

The product he linked to specifically stated it was . But you didnt bother to foillow te link did you?

Oh FFS.

Is all your DIY knowledge from manufacturers brochures?

>

[The Natural Philosopher]

Polystyrene is banned except in floor screeds. Extreme fire risk.

[Fredxx]

Best tell Travis Perkins:

And Jewsons And B&Q

[Fredxx]

Unless you put insulated taper edge plasterboard under screeds?

Where do you get your information from?

[The Natural Philosopher]

And the residents of Grenfell towers..

BCO wouldn't let me out it in the walls back in 2000.