Bathroom Insulation

[jus001]

Hello,

I'm in the middle of renovating my bathroom and after stripping it back to the brick I have built stud frames over the walls which will be covered in cement board prior to tiling.

Two walls are external (2 courses of brick and render on the outside), one is a party wall and the other a stud partition.

I have enough space to get some 60mm foam insulation board inbetween the studs and with any luck make the room a little warmer.

I have copper pipework running around the bottom of the walls behind the studs serving that radiators and sink etc. This is clipped to some OSB that is screwed to the brick.

I guess it's not a problem laying insulation over/around the pipes?

Would it be advisable to fit a vapour barrier between the cement board and the studs? If so, should this go over the pipework too?

Also, how would I run cables through the walls? There is a 30mm or so gap between the stud and the brick where the pipes are running. Is it acceptable to run cables in this void behind the insulation?

Thanks!

J

 

[theprinceofdarkness]

This gap is called a "service void", it is normally in front of the insulation because then you don't have to pierce the insulation to get your cables/pipe out of the wall.
Frank

 

[oldbutnotdead]

Cables in your 30mm void- yes they're fine, clip them every so often so they're in contact with the wall not the insulation. Where cables have to pass through the insulation you might want to think about using short lengths of conduit (haven't got the derating figures handy for cable through PIR but its quite a lot).

 

[freddiemercurystwin]

I have enough space to get some 60mm foam insulation board inbetween the studs

Actually I hear custard is popular nowadays.

 

[^woody^]

Pipes in foam insulation. Insulation tight against the wall, with no air gaps. You wont need a vapour barrier

Cable in conduit, trunking or capping. In these situations it may be best to cut a slight recess in the insulation, fit cable capping inverted to form a barrier to the insulation then tape the cable in. The cable then lies on the back of the cement board to allow heat to dissipate.

 

[jus001]

I have enough space to get some 60mm foam insulation board inbetween the studs

Actually I hear custard is popular nowadays.

Does it have to be home made or would instant do? How about lumps - would that affect thermal resistance?

Assuming I can't source enough custard or it leaks out of the bottom of the wall, are you implying 60mm foam boards are not worth the effort?

 

[^woody^]

He's from Ambrosia land, he has a thing about custard.

60mm of anything will do. Foil coated insulation like celotex will be the best for any given thickness.

 

[freddiemercurystwin]

I had some birds custard on my spotted dick last night.

 

[^woody^]

I had some birds custard on my spotted dick last night.

Nah, I bet you were doing a bit of DIY again Freddy.