ᐅ Watertight concrete structure ("white tank") and drainage: when is each required?
Created on: 1 Oct 2011 19:01
S
speerHello everyone,
can someone explain to me when a "white tank" (watertight concrete shell) is required? A representative visited us a few days ago and said it depends on many factors whether this measure is necessary. In his opinion, it would be unnecessary if the drainage can be connected to the sewer system.
So when exactly is it needed, and can I have this clarified before buying the house? Can someone explain this to me?
can someone explain to me when a "white tank" (watertight concrete shell) is required? A representative visited us a few days ago and said it depends on many factors whether this measure is necessary. In his opinion, it would be unnecessary if the drainage can be connected to the sewer system.
So when exactly is it needed, and can I have this clarified before buying the house? Can someone explain this to me?
P
perlenmann2 Oct 2011 08:57There is a geotechnical survey for this purpose. It is not the house builder but a geologist who determines what is necessary based on your plot and the existing soil conditions.
B
Bauexperte2 Oct 2011 10:49Hello,
Water can affect the exterior surfaces of buildings in various forms: as ground moisture, as non-accumulating seepage water, as temporarily accumulating seepage water, or as either hydrostatic (pressurized) or non-hydrostatic water. The choice of waterproofing depends on the type of water exposure, the soil conditions, the load requirements, and the intended use of the building.
There are two basic types of building waterproofing: the “black tank” and the “white tank.”
Black Tank
For the black tank, the building components that require sealing are covered on all sides with a continuous waterproof membrane according to DIN 18195. This involves applying waterproof sheets made of bitumen or plastic on the outside of the building (external waterproofing), which are then pressed against the building walls or base slab by the attacking water.
White Tank
With the white tank, no additional waterproof membranes are necessary due to its design. The foundation slab and exterior walls are constructed as a fully enclosed shell made of concrete with high resistance to water penetration according to DIN EN 206-1 and DIN 1045-2. This type of concrete is also called waterproof concrete or WU concrete. The construction follows the guideline “Waterproof Concrete Structures” by DAfStb. The white tank is typically built to full floor height, either as in-situ concrete with system formwork or using prefabricated triple-wall elements.
Whether your soil conditions require special waterproofing for the basement will be stated in the soil report, which you should always have prepared by a geotechnical expert before starting construction!
Having an opinion is like having faith in church. The seller can—if they have already built in the development area—make an educated guess; but nothing more. I have often experienced cases where the soil conditions were fine on one semi-detached house plot, but just a few meters away, problems occurred; in doubtful cases, this can become quite expensive and will definitely exceed the estimated additional costs.
Kind regards
speer schrieb:
When exactly is it needed, and can I clarify this before buying the house? Can someone explain it to me?
Water can affect the exterior surfaces of buildings in various forms: as ground moisture, as non-accumulating seepage water, as temporarily accumulating seepage water, or as either hydrostatic (pressurized) or non-hydrostatic water. The choice of waterproofing depends on the type of water exposure, the soil conditions, the load requirements, and the intended use of the building.
There are two basic types of building waterproofing: the “black tank” and the “white tank.”
Black Tank
For the black tank, the building components that require sealing are covered on all sides with a continuous waterproof membrane according to DIN 18195. This involves applying waterproof sheets made of bitumen or plastic on the outside of the building (external waterproofing), which are then pressed against the building walls or base slab by the attacking water.
White Tank
With the white tank, no additional waterproof membranes are necessary due to its design. The foundation slab and exterior walls are constructed as a fully enclosed shell made of concrete with high resistance to water penetration according to DIN EN 206-1 and DIN 1045-2. This type of concrete is also called waterproof concrete or WU concrete. The construction follows the guideline “Waterproof Concrete Structures” by DAfStb. The white tank is typically built to full floor height, either as in-situ concrete with system formwork or using prefabricated triple-wall elements.
Whether your soil conditions require special waterproofing for the basement will be stated in the soil report, which you should always have prepared by a geotechnical expert before starting construction!
speer schrieb:
...In his opinion, it would be unnecessary if the drainage can be connected to the wastewater system.
Having an opinion is like having faith in church. The seller can—if they have already built in the development area—make an educated guess; but nothing more. I have often experienced cases where the soil conditions were fine on one semi-detached house plot, but just a few meters away, problems occurred; in doubtful cases, this can become quite expensive and will definitely exceed the estimated additional costs.
Kind regards
Hello everyone,
my experience with building companies has been really alarming. We had discussions with 6 companies. Only 2 companies advised us to have a soil survey carried out beforehand!
One representative said to first remove the soil and then you can see if a waterproofing membrane is necessary. That really makes you feel well advised.
my experience with building companies has been really alarming. We had discussions with 6 companies. Only 2 companies advised us to have a soil survey carried out beforehand!
One representative said to first remove the soil and then you can see if a waterproofing membrane is necessary. That really makes you feel well advised.
S
Stefanlein4 Oct 2011 20:13speer schrieb:
Hello everyone,
In his opinion, it would be unnecessary if the drainage could be connected to the sewage system. Then ask whether it is not only POSSIBLE but also ALLOWED.
C
Christian AHS14 Jul 2013 16:06Hello,
I had to plan a waterproof basement due to upcoming water issues. Next week, the basement ceiling and walls will be backfilled.
After that, I will apply the perimeter insulation myself. However, I’ve come across very different opinions about the adhesive method.
The basement is partly embedded in a slope, so the front will be at ground level and open. I’ve already figured out that I need two types of insulation boards here (with and without mesh for plaster).
But about the bonding itself – the basement surface is clean and smooth (I started preparing last Friday).
My builder recommends applying bitumen with a notched trowel, saying that’s good enough. My building materials supplier says a special foam adhesive would be more economical, less messy, and sticks just as well to clean concrete.
One customer also suggested securing the boards with anchors in visible areas (because of the weight of the plaster). But anchors in a waterproof basement? I don’t want to drill into my watertight shell.
Generally, I’ve found that the bitumen option is typical – does that product require an activator or something?
Would using foam adhesive make sense? It would presumably be easier.
Also, is the issue with the boards in the visible area and the weight of the plaster really such a problem? If the boards are properly glued to the wall and rest on the gravel bed at the bottom, there SHOULDN’T be any sagging (this concerns the north side, by the way).
Thanks for any advice.
Regards,
Chris
I had to plan a waterproof basement due to upcoming water issues. Next week, the basement ceiling and walls will be backfilled.
After that, I will apply the perimeter insulation myself. However, I’ve come across very different opinions about the adhesive method.
The basement is partly embedded in a slope, so the front will be at ground level and open. I’ve already figured out that I need two types of insulation boards here (with and without mesh for plaster).
But about the bonding itself – the basement surface is clean and smooth (I started preparing last Friday).
My builder recommends applying bitumen with a notched trowel, saying that’s good enough. My building materials supplier says a special foam adhesive would be more economical, less messy, and sticks just as well to clean concrete.
One customer also suggested securing the boards with anchors in visible areas (because of the weight of the plaster). But anchors in a waterproof basement? I don’t want to drill into my watertight shell.
Generally, I’ve found that the bitumen option is typical – does that product require an activator or something?
Would using foam adhesive make sense? It would presumably be easier.
Also, is the issue with the boards in the visible area and the weight of the plaster really such a problem? If the boards are properly glued to the wall and rest on the gravel bed at the bottom, there SHOULDN’T be any sagging (this concerns the north side, by the way).
Thanks for any advice.
Regards,
Chris
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