Party wall insulation

[Lfcsixtimes]

In a solid block wall situation, when an adjoining external wall is being insulated, is it recommended to insulate the party wall?

Could low external temperatures creep into the block up through the party wall? I was only going to sound insulate but may now PIR insulate instead to prevent any future issues unless it’s a non-issue.

In the diagram I’ve attached, the green would be where I was going to just sound insulate.

Thanks

 

[kp00110]

I would think its a waste. If anything if your neighbour is uninsulated at present they will be cranking up the heating above the level in your place and you will get more incoming heat from it than heat lose

 

[Diver Fred]

I'd insulate. That wall will be a cold spot - liable to be a condensation point so a target for black mould. Thermal insulation will also be a noise suppressant

 

[Lfcsixtimes]

1 all by the looks of it! I would be sealing the corner and to ceiling as much as I can, but it really is a question of if the moisture can evaporate from the neighbours heating their room, or if the inside of my party wall will be cold.

Some heat from my side will penetrate through soundproofing and potentially warm up the block behind. Difficult!

 

[SFK]

If you are going to sound insulate, use rockwool sound insulation slab and get best of both worlds as it will also thermally insulate.
PIR does not stop sound.

Rockwool Sound Insulation Slab - 100 x 600 x 1200mm | Wickes.co.uk

Rockwool Sound Insulation Slab - 100 x 600 x 1200mm

www.wickes.co.uk

 

[cdbe]

We have no money and barely run our heating, our neighbours are wealthy pensioners and have their heating on constantly - I would never insulate our party wall.

 

[RandomGrinch]

Similar for me, solid stone wall terrace - 60% of my 'exterior' walls are party walls.
My rads upstairs have remained off this winter - I think my next door neighbour has a crypto mining rig! Toasty!

 

[Lfcsixtimes]

Wool might be a good idea actually… only reason I discounted it was because I was fixing direct.

In terms of cold pushing through from the external wall up the party wall, is this possible?

 

[Diver Fred]

Yes, certainly is possible to feel the cold progressing along the wall. I've seen a figure of 16" /400mm from the inside of an outside wall quoted but presently cannot remember where I saw it published.

 

[Lfcsixtimes]

Interesting….

Should I stick with the same foil based PIR I’m using on the external wall or could I down-rate to wool or similar?

 

[RandomGrinch]

Interesting….

Should I stick with the same foil based PIR I’m using on the external wall or could I down-rate to wool or similar?

PIRs not the best for sound insulation.
If as in some of our cases, the main benefit of any insulation on the party wall, would be for sound insulation.
In which case (as mentioned above) the Rockwool batts would be a very good choice - good for stopping sound transmission, and good enough to stop heat loss in the corner of the room.

 

[Lfcsixtimes]

Thanks. I think I’ve finalised plans with rockwool. Excuse the rudimentary drawing, but the external wall will have a VCL in term of foil, would I need to extend this into the party wall?

I need to stand off the stud as the wall so so uneven. So rockwool will be between the studs.