Thank you for the response.
It just says extensive slabs and I have no idea what that means. Other than that it probably involves some form of slabs that have been laid out extensively. However, I don't know what it looks like under these slabs because it's not clear from the drawing. Nor how many slabs or how they are dimensioned. Hence the question.
There should have been some form of standard in the 50s?. The house is a 1 1/2-story with a basement.
It just says extensive slabs and I have no idea what that means. Other than that it probably involves some form of slabs that have been laid out extensively. However, I don't know what it looks like under these slabs because it's not clear from the drawing. Nor how many slabs or how they are dimensioned. Hence the question.
There should have been some form of standard in the 50s?. The house is a 1 1/2-story with a basement.Spread footings consist of a narrow concrete slab that follows the foundation wall. In section, it looks like an upside-down T. The width is often in the range of 60 - 100 cm for villas. The slab can rest directly on the subsoil or on a layer of macadam. Often, the slab is situated a bit below the basement floor, perhaps 30 - 60 cm.
Do the tiles pose any concern if one plans to dig up the basement floor for sewage replacement and embedding of underfloor heating?
Could these tiles be partly the cause of cracking in the foundation? If a footing had been cast instead, maybe it would have been slightly more stable?
Could these tiles be partly the cause of cracking in the foundation? If a footing had been cast instead, maybe it would have been slightly more stable?
"Do the slabs pose any concern if you plan to break up the basement floor to replace the drainage and embed underfloor heating?"
Probably, it depends on whether you can follow the same path with the new drainage pipes.
It can be a lot of work if you have to go through the slab. It is reinforced!
Another problem may arise if the height is insufficient for the insulation you want under the underfloor heating. But it's possible to reduce the insulation a bit right at the slabs.
"Could these slabs be partially the cause of cracks in the foundation?"
No!
"If instead a sula was poured"
A sula is the same as spread slabs.
Probably, it depends on whether you can follow the same path with the new drainage pipes.
It can be a lot of work if you have to go through the slab. It is reinforced!
Another problem may arise if the height is insufficient for the insulation you want under the underfloor heating. But it's possible to reduce the insulation a bit right at the slabs.
"Could these slabs be partially the cause of cracks in the foundation?"
No!
"If instead a sula was poured"
A sula is the same as spread slabs.
Thank you very much for the information. We probably need to think a bit about how we should proceed. However, we still need to dig up and replace the sewage pipes before we renovate the shower room in the basement. It will be exciting to see if the tiles cause any trouble.
Hilexus said:
Old thread but very relevant for me... I have a similar description (spread slabs) in my building permit documents from 1968 but I can't figure out how it is actually done. If you're still active, I'd really appreciate hearing how it went and what it looked like. Did you manage to locate where the "boundary" for the foundation/floor was? How thick was your floor? Did the slabs cause any problems?
Maybe someone else who has faced similar issues with spread slabs??
My challenge is that I find it difficult to determine if I have a solid slab or foundation (spread slabs) with a secondary poured floor. What I know is that concrete masonry units are built up on the slab or foundation, and the "projection" below ground varies from a few centimeters to perhaps a maximum of 8-9 cm. The actual foundation or slab is about 30 cm thick from the outside, and when I drilled in the room where I intend to excavate, the floor is at least 20 cm thick (the drill didn't go further). When I hit this room with a crowbar, the floor is solid, while in the garage, some sections are equally solid while others are relatively "hollow." Could it be that these slabs are under the floor even though there's no load-bearing wall right there...
I guess I'll have to jackhammer a hole and try to determine how it's constructed. Feeling a bit unsure