ᐅ Is side waterproofing of the foundation slab necessary to prevent moisture intrusion?

Hello everyone,

We are constructing a load-bearing concrete slab, on top of which a prefabricated house will be placed. The house manufacturer will install a flexible, bitumen-free moisture barrier between the slab and the wall to prevent rising damp.

The build-up from the ground up is as follows: load-bearing soil (rocky substrate, no groundwater), 30 cm (12 inches) of compacted crushed stone 0/32 with a surrounding frost skirt made of crushed stone, 2 cm (1 inch) sand bedding, 10 cm (4 inches) insulation with thermal conductivity class 40, a membrane, and a 25 cm (10 inches) load-bearing concrete slab. After the house is erected, 6 cm (2.5 inches) of perimeter insulation will be applied to the slab from the outside.

Question: Does the concrete slab need to be sealed against moisture on the sides? If so, how?

Regards,
sciliar

Hi,
the perimeter insulation goes all the way down to the insulation of the foundation slab.

Next week, our roofer will apply a special high-adhesion membrane on the primer—very thick, similar to a heavy-duty pond liner.

Later, the XPS boards will be attached to the sides of the foundation slab, or at least that’s how it will be done (the perimeter insulation will be completed by the painter/plasterer next year).

However, since a wooden house is built on the foundation slab in our case, extra care must be taken to prevent any moisture damage or “wet feet.”

superzapp schrieb:

Hi,
the perimeter insulation goes all the way down to the insulation of the concrete slab.

In our case, next week the roofer will apply a special membrane on the primer – a very thick one, similar to a very thick pond liner?

Later on, the XPS boards will be attached to the sides of the concrete slab, or at least that’s how it will be done (the perimeter insulation will be installed by the painter/plasterer next year).

However: We have a timber house on the concrete slab. We need to be especially careful to prevent any "wet feet" (moisture damage) here.

We are also having a timber house. The builder seals all walls at the bottom against the concrete slab.
The concrete slab is done by a local concrete contractor. The question is: in addition to the perimeter insulation, is a moisture barrier also required on the sides? Does this need to be connected with the membrane under the concrete slab? How is that done?

Take a look at the last few pages of my house building thread; there are several pictures showing the side area of the base plate. In 8 days, the roofer will come and apply the mentioned waterproofing. I will take detailed photos anyway and will gladly share them then.

superzapp schrieb:

Take a look at the last pages of my house-building thread; there are several pictures showing the side area of the base plate. The roofer will come in 8 days to apply the mentioned waterproofing. I will take detailed photos then and will be happy to share them.

Thanks, yes, I would be interested in the photos.
Do you have a link to "your" thread? When I search here, I get almost 600 results.

Certainly. Internal links are not prohibited, are they?

https://www.hausbau-forum.de/threads/bau-eines-mehrfamilienhauses-bzw-2-doppelhaushaelften-nach-kfw40.33918/post-446909