Insulating a single skin utility room

[angliojoe]

Hello all,
I am planning on taking my single skin utility room back to brick and then sticking 50mm of insulated plasterboard to it with foam adhesive. The room is currently off of my bathroom accessed by an internal door so is very very cold but damp free (only wetness on wall is from condensation).
Im thinking of using this: https://www.buildbase.co.uk/insulat...ard-tapered-edge-2400x1200x50mm-10353-2800246

Without hiring someone to calculate U values, could anyone advise on if the 50mm thickness will do the job to keep the room warm? Is that overkill? Is the above product any good?

Any advice would be appreciated.
Thanks.

 

[Mr Chibs]

50mm will be better than nothing, but thicker would be better... think regs may require 100mm but wait for someone to post, who knows this... if you are bothered.

I've got 50mm on my walls, and it's made a big difference in comfort... mine is solid double skin brick house.

Separate insulation and plasterboard sheets might be cheaper.
There should also be a few mechanical fixings to hold the sheets to the wall.
You can use insulation washers (ebay) and long screws for example.

 

[noseall]

Without hiring someone to calculate U values, could anyone advise on if the 50mm thickness will do the job to keep the room warm? Is that overkill? Is the above product any good?

Any advice would be appreciated.

50mm EPS is nowhere near enough and certainly would not satisfy Building Regs. It's not just the walls either. Have you considered the floor and roof insulation? With it being a bathroom, you really should be looking at high standards of insulation and fitting and paying attention to VCL (flat roof?) and venting etc.

80mm PIR foil sandwich (Celotex, Kingspan etc) would be a bare minimum for a single skin structure but 100mm is more practical as it's widely available. 80mm is one of those impractical silly sizes that designers, architects and surveyors bandy about but can't find it on builders merchants shelves.

 

[JP_]

50mm will be better than nothing, but thicker would be better... think regs may require 100mm but wait for someone to post, who knows this... if you are bothered.

I've got 50mm on my walls, and it's made a big difference in comfort... mine is solid double skin brick house.

Separate insulation and plasterboard sheets might be cheaper.
There should also be a few mechanical fixings to hold the sheets to the wall.
You can use insulation washers (ebay) and long screws for example.

I was about to say the same.

50mm Kingspan (or equiv)
Plasterboard
All stuck together with sticky foam
And some washers and screws if you feel they are needed

My shopping list:
https://www.wickes.co.uk/Kingspan-TP10-Insulation-Board---2400-x-1200-x-50mm/p/180436
https://www.wickes.co.uk/Knauf-Plasterboard-Tapered-Edge---9-5mm-x-1-2m-x-2-4m/p/220207
https://www.wickes.co.uk/Everbuild-Pinkgrip-Dry-Fix-Wall-Adhesive-Foam---750ml/p/132396
https://www.amazon.co.uk/gp/product/B07J4LX3Y7
https://www.screwfix.com/p/turbo-si...-multipurpose-screws-5-x-120mm-100-pack/26249

 

[angliojoe]

Thanks everyone. The bathroom is double skinned with cavity insulation and I'm happy with that. The issue is all coming from the cold tiny utility room off the back of it which is the single skin part. With it only being 83cm wide at the moment, i think 50mm on the walls is probably the limit of it being usable. Floor is fine and i will be taking down part of the plasterboard ceiling to see if the roof has been insulated too. I'm thinking of just using it for storage and potentially get a tumble dryer in there so just need it to be warm enough to not make the bathroom cold.

@JP_ are you suggesting attach the insulation to the wall with foam and then plasterboard on top? Wouldnt using seperate insulation and plasterboard require it all to be battened out and attached mewchically?

Thanks again for all the advice everyone.

 

[JP_]

Wouldnt using seperate insulation and plasterboard require it all to be battened out and attached mewchically?

No, you can stick it all on. For many of my walls I only used glue, I mostly used screws when putting tilebacker board over insulation, but saying that, did pop a couple of anchors in just in case.

The glue should hold forever, in the same way the glue on the insulationed plasterboard doesn't fail, but the reason given is if there is a fire, the boards will come away from the wall with the heat (and burn). My thinking is, if there is a fire that hot, I've already lost my house!

 

[angliojoe]

Thanks @JP_ , I’m going to go with your option, thanks for providing the list of stuff to get. A couple last stupid questions. If I was to use those screws to add some extra fixings to it, i still need to use rawl plugs not just pre drill a hole and screw in? Also the screws are put in after both the insulation and plasterboard have been fitted to the wall with foam and then just drive the screws into the plasterboard so the heads aren’t showing and skim over?
Thanks.

 

[JP_]

Yeah, that's what I have done. Used brown plugs, 7mm masonry drill bit, put the screw in the washer, plug on the end of the screw (one hand turn) push in place, tap in with hammer, then screw in. With screws into external wall and skim out might get cold spots - there are plastic washers you can use to reduce this. This is partly why I have only really done this where I am tiling.

The foam is not the easiest to handle (my plasterer actually tried and failed). You have to spray on a wait 4 minutes, then push on to the wall, and hold in place. It will move if you release pressure. I have probably spent an unreasonably large part of the last 5 years leaning against an insulation board while the foam sets. In a small room you can prop it more easily though.