Insulate a masonry wall on the inside?

[kirilian]

I have a wall made of insulated lightweight concrete blocks. It works great except in one spot where an electrical cabinet has been installed. The wall is completely cold in the winter, and I guess there's a hole straight through for the cabinet to fit.

I'm thinking of cutting open the wall from the inside to see what it looks like and insulate it. Inside, it's just framed and chipboard+gypsum.

But what's the best way to insulate a masonry wall on the inside? There probably isn't much space for insulation.

 

[Liteavvarje]

Measure the depth of the cupboard and the stone, I believe there isn't much left, I have seen a house where it was framed and insulated on the inside, but then the water came into the same wall.

 

[justusandersson]

If there isn't space, there isn't. Considering the entire wall's surface, it must be negligible. Make sure it is tight.

 

[kirilian]

it probably needs to be insulated because the room that is behind it becomes ice-cold in the winter because of this. So I'm thinking of some sort of insulation with the best possible insulating ability, whatever that might be...

 

[justusandersson]

It's difficult to give good advice without knowing more about the wall's construction, both generally and behind the electrical cabinet. There's probably a snag there because I find it hard to imagine that the small area an electrical cabinet occupies could make it so cold.

 

[Polacoloco]

Small uninsulated holes cool a lot in the winter, especially if there is a draft. Is it the facade cabinet for the electricity meter that is on the other side?

 

[justusandersson]

Small uninsulated holes cool a lot in the winter, especially if there's a draft.

I wouldn't express it that way. If it's only the insulation that separates the surfaces, the effect is negligible in a reasonably large room. It's easy to demonstrate this with a numerical example. However, if there are holes straight through causing a draft, then it's a different situation.

 

[kirilian]

Small uninsulated holes cool a lot in winter, especially if there is a draft. Is it the facade cabinet for the electricity meter that is on the other side?

Yes, it is the electricity meter that is there.

 

[kirilian]

I wouldn't put it that way. If it's only the insulation that differentiates the surfaces, the effect is negligible in a reasonably large room. It's easy to demonstrate this with calculations. However, if there are holes straight through that cause drafts, then it's a different situation.

Yes, it's cold anyway. It feels like there are holes straight through. I think the guys who built the house simply sawed a big hole for the electrical cabinet and then just laid the inner wall on top.

So the place to insulate is equal to the depth of a stud! What's the best way to do it?

 

[Polacoloco]

Warm humid indoor air condenses on cold surfaces. I don't know how your wall is constructed but it should be studs, insulation, plastic, drywall. But I'm just an elevator technician so I would wait for a professional answer

 

[kirilian]

Warm humid indoor air condenses on cold surfaces. I don't know how your wall is constructed but it should be studs, insulation, plastic, drywall. But I'm just a lift technician so I would wait for a professional answer

Plastic closest to the indoor air, right?

 

[Polacoloco]

Plastic on the innermost part towards the indoor air, right?

Yes, that's how it should be. But maybe you should check first if there really is a hole straight through the wall behind the facade cabinet.

 

[kirilian]

Yes, that's how it should be. But maybe you should first check if there really is a hole straight through the wall behind the facade cabinet.

I guess I'll have to cut open the wall to check if it's the back of the electrical cabinet I'm seeing behind the interior wall. There probably isn't much room to insulate, unfortunately, so I don't really know how to solve this?

 

[Finndjävel]

Polyurethane boards can be used if you have limited space but want maximum insulation efficiency. They were previously called SPU but are now called Kingspan Therma.
There is also a version with a gypsum board already mounted on these boards. They don't need any studs or anything; you just glue them directly onto the concrete wall with polyurethane foam.

https://www.kingspan.com/se/sv-se/produkter/isolering/therma/therma-tw56-isolergips

 

[kirilian]

You can use polyurethane boards if you have limited space but want maximum insulation. They used to be called SPU but now they're called Kingspan Therma. There is a variant with drywall already mounted on these boards. They don't need any studs or anything; you just glue them with polyurethane foam directly on the concrete wall.

[link]

Those boards seem really good. I hope there's 30 mm space for one of those. Thanks for the great tip. Should be able to glue directly onto the cinder blocks, then.