Insulate bathroom slab from underneath, from the cellar ceiling?

[Hus&Kärlek]

Hello! Building a small toilet and separate shower room. The toilet and parts of the shower room will be built on top of the slab visible in the picture (the remains of filler, tiles, and the toilet pipe visible on the left in the picture are gone now). The slab is cast around the chimney breast and is likely original from the house's construction in the 40s. About 200 mm thick.

Is it possible to insulate that slab from below? We don't want underfloor heating. Below is a full-size basement, unfinished, uninsulated (some form of blocks or casting in the basement walls, with poor drainage).

We want to insulate from below to avoid building up the floors more than necessary (planning to apply self-leveling compound and then tiles, which will end up just above the surrounding floors). And the parts of the shower that are not placed on the slab will have reinforced joists with EPS-cement (which, as I understand, is insulating in itself).

Hope someone has some tips!

 

[surris]

Hi! Building a small toilet and separate shower room. The toilet and parts of the shower room will be built on top of the slab visible in the picture (the remains of leveling compound, tiles, and toilet pipe visible to the left in the picture are gone now). The slab is cast around the chimney and is likely original from the house's construction in the 40s. About 200 mm thick.

Is it possible to insulate that slab from underneath? We don't want underfloor heating. Below is a full-sized basement, unfinished, uninsulated (some form of block or casting in the basement walls, with poor drainage).

We want to insulate from underneath to avoid adding more to the floors than necessary (going to lay leveling compound and then tiles, will be just over surrounding floors). And the parts of the shower not laid on the slab will be reinforced joists with EPS cement (which as I understand is insulating in itself).

Hope someone has some tips!

Is the basement heated? If it is heated, then I see no major reason to insulate. But yes, it can be done anyway.

 

[Hus&Kärlek]

Is the basement heated? If it's heated, I don't see much reason to insulate. But yes, it can be done anyway.

Hi! No, not a heated basement. Oh, sounds great that it can be done. What do you think could be good solutions? Material/technique. Thanks!

 

[Tomture61]

If the cement slab only extends as seen in the picture and does not constitute the slab for the entire house, then why not.
For your own curiosity, make a comparison with and without insulation, during the winter months then!

 

[surris]

Hi! No, not a heated basement. Oh, sounds great that it can be done. What do you think could be good solutions? Material/technology. Thanks!

A ground slab of stone wool. Just straight on from underneath.

 

[Hus&Kärlek]

If the cement slab only extends as seen in the picture and does not constitute the slab for the entire house, then why not.
For your own curiosity, make a comparison with and without insulation during the winter months!

Good idea, since the completion of the rooms themselves is not dependent on the insulation. Thanks!

 

[Hus&Kärlek]

A ground slab of stone wool. Just straight on from underneath.

Great, thanks! Sounds simple and good!