Plaster/masonry an insulation pipe on a plastered lightweight concrete wall

[Daniel Larsson]

Hi, I'm starting to get a bit cold feet now about my great idea to cast the prisol pipes into the radiator. The wall is built with Finja Exakt (10cm insulation in the middle of the concrete block). On top of this, there is a metal mesh and 5-10mm plaster, done by a professional.

What worries me now is that it might crack when the pipes get a little warm, and maybe the plaster won't adhere to the prisol plastic? Do I need a mesh over them and how deep must the pipe be embedded to get a good plaster? I assume the 3mm they are under the wall edge now isn't enough? See pictures! Very grateful for all tips. Perhaps one should start with house fix at the bottom? I was thinking of embedding some form of claw fixture to hold the pipes in place so they don't move. Is this necessary, do you think?

 

[neo11]

See no problem with applying 3mm c mortar in rounds directly on the pipes. Pre-moisten a bit.
Mortar is a stone material and doesn't really have problems with heat like wood and metal can have.
I don't think you need a mesh either since it is quite thick.
The only problem might be at the top if it’s only 3 mm, it is thin for plaster and can crack.
But you wouldn’t have room for a mesh there, so figure something out.
Don't use husfix.

 

[Alexn72]

In my opinion, 3mm plaster is too little.
But otherwise, just go for it.
I usually fix the pipes with nails or screws and then dab on plaster in about 2 places per meter, when they have set, remove the screws and plaster.

 

[Daniel Larsson]

Thanks! Now I have a little idea.

 

[BSOD]

3mm feels little.

It's easy to remove a few more mm to get a little better coverage on the pipe. Considering it's so little, I would have taken a cheap chisel and knocked out a couple more mm.

https://www.jula.se/catalog/verktyg...ch-trasnidarverktyg/stamjarn/stamjarn-125323/