Hello everyone,
About 15 minutes ago, I was shocked to discover a depression has recently formed in the kitchen floor.
About the building itself: an old building, condominium, from the 1950s or 1960s. The floor consists of wood, underneath that should be ash used as insulation, and below that wood again, which forms the ceiling of the apartment below.
Tiles are laid on the wooden floor. Some of the tiles have cracked for some time already, and I have been wondering about the cause. I assumed it was because the wooden floor is slightly springy.
I noticed the depression a few days ago and wondered how I never saw it before. But just now, I discovered a gap has formed between the tiles and the baseboards, which is up to about 3cm (1.2 inches) wide at its largest point.
I had already removed one tile at the edge of the depression some time ago, and the wood underneath looked completely dry and undamaged.
Tomorrow, I plan to remove a tile directly within the depression to take a closer look.
Do you have any advice for me? Or is this kind of “movement” normal for an old building? What could be the causes? Is there any risk involved?
Thanks for your answers
freid
About 15 minutes ago, I was shocked to discover a depression has recently formed in the kitchen floor.
About the building itself: an old building, condominium, from the 1950s or 1960s. The floor consists of wood, underneath that should be ash used as insulation, and below that wood again, which forms the ceiling of the apartment below.
Tiles are laid on the wooden floor. Some of the tiles have cracked for some time already, and I have been wondering about the cause. I assumed it was because the wooden floor is slightly springy.
I noticed the depression a few days ago and wondered how I never saw it before. But just now, I discovered a gap has formed between the tiles and the baseboards, which is up to about 3cm (1.2 inches) wide at its largest point.
I had already removed one tile at the edge of the depression some time ago, and the wood underneath looked completely dry and undamaged.
Tomorrow, I plan to remove a tile directly within the depression to take a closer look.
Do you have any advice for me? Or is this kind of “movement” normal for an old building? What could be the causes? Is there any risk involved?
Thanks for your answers
freid
Remote diagnoses of such structural damage are not reliable, especially since information about the structural context is missing. These details should be documented with existing plans or determined on-site through a building survey. The composition of the ceiling structure would need to be known to make any assumptions about the causes of the deformation. Structural movements beyond those caused by temperature and humidity changes are not normal and, in your case, should not be a factor.
For a building from the 1950s or 1960s, I would not necessarily expect a timber beam ceiling but rather a resource-efficient concrete slab or a precast panel ceiling. If deformations of the raw ceiling were the actual cause, they would also be noticeable on the floor below, as well as in general structural movements such as crack formation.
You may need to conduct an on-site inspection with an architect or structural engineer and at least open the ceiling in one spot beforehand to clarify the structural composition and installation situation of the ceiling. It may also be necessary to assess the entire building if the deformation is not solely local. For a timber beam ceiling with a plank floor structure, the most common causes would basically be moisture damage at the wall support areas of the beams or moisture damage in the plank floor due to leaking plumbing pipes (drip leakage) or a siphon.
For a building from the 1950s or 1960s, I would not necessarily expect a timber beam ceiling but rather a resource-efficient concrete slab or a precast panel ceiling. If deformations of the raw ceiling were the actual cause, they would also be noticeable on the floor below, as well as in general structural movements such as crack formation.
You may need to conduct an on-site inspection with an architect or structural engineer and at least open the ceiling in one spot beforehand to clarify the structural composition and installation situation of the ceiling. It may also be necessary to assess the entire building if the deformation is not solely local. For a timber beam ceiling with a plank floor structure, the most common causes would basically be moisture damage at the wall support areas of the beams or moisture damage in the plank floor due to leaking plumbing pipes (drip leakage) or a siphon.
Hello wpic,
First of all, thank you very much for your post.
I worked a night shift last night and today I tore up the floor because I’m really worried that something might collapse.
Even though it’s difficult to make a “remote diagnosis,” I wanted to ask you again if you have any thoughts on the structural stability or risk of collapse based on the new information I discovered today.
When tearing up the floor, I found screed/concrete and I suspect that it supports the floor, so there may be no danger of collapse.
Here are the facts:
Under the tiles in the newly formed dip, in an area of about 1 x 1 meter (3 x 3 feet), all the wood is rotten, crumbling, and blackened. However, everything is completely dry. The previous tenant had their sink there. In my layman’s opinion, this is clearly an old water damage issue.
A crossbeam has broken because of this, causing the dip.
The floor construction is (from top to bottom):
Tiles
Chipboard (rotten in the affected area)
Wooden planks (rotten in the affected area)
Crossbeams (rotten in the affected area); spacing about 30-40 cm (12-16 inches)
The crossbeams rest on smaller concrete blocks.
The concrete blocks rest on screed/concrete.
Under the crossbeams and between the smaller concrete blocks there is ash.
The apartment was an attic about 40 years ago and was then converted into living space. Next to the apartment is an attic room (on the same level as the apartment) that was also converted into living space last year, and there is also load-bearing screed (examined by an architect and a structural engineer) at exactly the same height. It appears to be the “same” screed.
I’m completely exhausted now, so it would be great if you could write a few reassuring words so I can sleep calmly.
Kind regards
freid
First of all, thank you very much for your post.
I worked a night shift last night and today I tore up the floor because I’m really worried that something might collapse.
Even though it’s difficult to make a “remote diagnosis,” I wanted to ask you again if you have any thoughts on the structural stability or risk of collapse based on the new information I discovered today.
When tearing up the floor, I found screed/concrete and I suspect that it supports the floor, so there may be no danger of collapse.
Here are the facts:
Under the tiles in the newly formed dip, in an area of about 1 x 1 meter (3 x 3 feet), all the wood is rotten, crumbling, and blackened. However, everything is completely dry. The previous tenant had their sink there. In my layman’s opinion, this is clearly an old water damage issue.
A crossbeam has broken because of this, causing the dip.
The floor construction is (from top to bottom):
Tiles
Chipboard (rotten in the affected area)
Wooden planks (rotten in the affected area)
Crossbeams (rotten in the affected area); spacing about 30-40 cm (12-16 inches)
The crossbeams rest on smaller concrete blocks.
The concrete blocks rest on screed/concrete.
Under the crossbeams and between the smaller concrete blocks there is ash.
The apartment was an attic about 40 years ago and was then converted into living space. Next to the apartment is an attic room (on the same level as the apartment) that was also converted into living space last year, and there is also load-bearing screed (examined by an architect and a structural engineer) at exactly the same height. It appears to be the “same” screed.
I’m completely exhausted now, so it would be great if you could write a few reassuring words so I can sleep calmly.
Kind regards
freid
My suspicion that leaking plumbing pipes may have caused this damage is almost confirmed. You should ask the architect who planned the rest of the attic conversion about the floor construction of the ceiling below your floor and, just to be sure, also about structural details of the concrete slab (thickness, assumed live load for the structural calculations submitted with the building permit / planning permission).
If the shell construction is sound, your next step would be to remove the entire old floor and have a proper new floor construction planned according to your requirements. Impact sound insulation is important here, as well as resistance to moisture. An old-style plank floor would therefore not be the best choice. If you want to install plumbing under the floor, this must be carefully planned and not improvised by the contractor on site. Leave nothing to chance with the tradespeople.
I would almost recommend having a qualified expert inspect your condominium unit, provided you are the owner and not a tenant. Such structural “legacy issues” often indicate that work has been poorly done elsewhere or at least not carried out according to recognized technical standards.
You can also ask the apartment owner for construction documents. They should have received a building specification at purchase, including detailed descriptions and material information about any renovation work done.
If you are only a tenant, you should not take any action yourself but inform the owner. Anything further is then not your responsibility.
If the shell construction is sound, your next step would be to remove the entire old floor and have a proper new floor construction planned according to your requirements. Impact sound insulation is important here, as well as resistance to moisture. An old-style plank floor would therefore not be the best choice. If you want to install plumbing under the floor, this must be carefully planned and not improvised by the contractor on site. Leave nothing to chance with the tradespeople.
I would almost recommend having a qualified expert inspect your condominium unit, provided you are the owner and not a tenant. Such structural “legacy issues” often indicate that work has been poorly done elsewhere or at least not carried out according to recognized technical standards.
You can also ask the apartment owner for construction documents. They should have received a building specification at purchase, including detailed descriptions and material information about any renovation work done.
If you are only a tenant, you should not take any action yourself but inform the owner. Anything further is then not your responsibility.
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