ᐅ Waterproof Basement – "Fresh Concrete Composite Membrane"

Created on: 13 Jul 2017 09:04
W
Wissi
Hello everyone,

this is about the method our house builder is using to create a waterproof basement. To be honest, I have never heard of this before, and there is very little information available online about it... and what there is mostly relates to commercial or office buildings.

The method is called "fresh concrete composite membrane" (FBVK #waterproof) with double-layer exterior walls 20cm (8 inches) thick.
One step down would be the "WU-basement" with double-layer exterior walls 24cm (9.5 inches), joint flashing. Of course, this option is also cheaper (approx. 3,000 €).

The plan is to set up a home office in the basement. Therefore, we would prefer it to be "properly sealed," ideally without high humidity caused by water-resistant concrete.

A soil report is not available yet!

Are you familiar with the first method? Have you had any experience with it or any opinions?
It would also be interesting to know whether insulation is possible at all if there is a "membrane" facing the soil on the outside.
Wissi6 Aug 2017 17:00
Hmm, thanks for the tip.

Our original idea was that the home office in the basement really should not experience any moisture from the outside.
We also wanted to keep it as dry as possible regarding wall coverings, flooring, and similar aspects.
77.willo6 Aug 2017 17:22
In a waterproof concrete basement, the humidity is not higher than in other types of construction—provided that the construction moisture is properly vented outside.
Wissi6 Aug 2017 17:37
Well, moisture diffusion remains an issue with a waterproof concrete basement. We want to avoid that.

The extra cost to upgrade from a standard waterproof concrete basement to waterproofing with a bonded waterproof membrane would be 3000€. It would be worth it to us.
77.willo6 Aug 2017 17:45
It is not. It seems to me to be an internet legend.
Wissi6 Aug 2017 18:07
The statement unfortunately seems somewhat unfounded… sorry to say it like that. But another user could come along in this forum and claim the exact opposite, which would cancel each other out. For example, I think it is.

A few references are always helpful in cases like this (no links, as they are not allowed):
- Building physics studies from TU Berlin
- Technical bulletins from the Information Center Concrete GmbH in Erkrath
- Publications from the German Committee for Reinforced Concrete

These are just three of many sources that confirm this.

What each person makes of it is up to them. For us, it means we prefer to play it safe. This also applies to potential cracks in the future. We want to enjoy the basement as long as possible and without any worries.
Yilmaz6 Aug 2017 18:14
Hello Wissi,

So you are getting an exterior wall insulation with additional membrane waterproofing? And that is supposed to cost 3000 euros more?

Then I would go for it!