Is lateral sealing of the base plate against moisture necessary?

Hello everyone,

We are creating a load-bearing foundation slab, on which a prefabricated house will be placed. The house manufacturer installs a barrier against rising moisture between the foundation slab and the wall (flexible, bitumen-free).

The structure from bottom to top is as follows: load-bearing ground (rocky terrain, no groundwater), 30 cm compacted gravel 0/32 and continuous frost skirt made of gravel, 2 cm sand bed, 10 cm insulation WLG40, foil, 25 cm load-bearing foundation slab.
The foundation slab is to be provided with 6 cm perimeter insulation on the outside after the house is built.

Question: does the foundation slab need to be sealed against moisture on the sides? If yes, how?

Regards, sciliar

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

Next week, the roofer will apply such a great special foil (super thick, similar to very thick pond liner?) on the primer for us!

Later on, the XPS boards will be attached sideways to the BP or it will be done that way (the perimeter insulation will be done by the painter/plasterer next year).

However: There is a wooden house on the BP for us. Here, you have to be much more careful that it doesn’t get "wet feet".

Hi, the perimeter insulation goes all the way down to the insulation of the slab. Next week, our roofer is applying such a great special foil (super thick, similar to very thick pond liner?) on top of the adhesion primer. Later, the XPS boards will be attached laterally to the slab or that's how it's going to be done (the perimeter insulation will be done by the painter/plasterer next year). However: A wooden house is standing on the slab in our case. You definitely have to be much more careful here that it does not get "wet feet".

We are also getting a wooden house. The house builder seals all walls downward against the slab. The slab is made by a local concrete builder. The question is, in addition to the perimeter insulation, does a moisture barrier also have to be applied on the side? Does it have to be connected to the foil under the slab? How is that done?

Take a look at the last pages of my house construction thread, there are some pictures where you can see the side area of the BP. In 8 days the roofer will come and then do the mentioned sealing. I will take detailed photos anyway and will gladly upload them then.

take a look at the last pages of my house construction thread, there are some pictures where you can see the side area of the BP. In 8 days the roofer will come and then do the mentioned sealing. I will take detail photos anyway and then gladly post them.

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

gladly. Internal links are not forbidden - are they?

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