ᐅ Concrete slab and house protected against moisture with dimpled membrane? Any experiences?

Created on: 21 Jun 2025 23:04

Hello dear homeowners,

Who has experience and can help me? I have been living in the house for 2 years, and now it’s time to work on the exterior landscaping. We have now installed dimpled membrane (drainage membrane) for the terraces, but it already seemed wrong to me. I have since read up on it and am still unsure. Did my construction company deliver a house without properly waterproofing the exterior or what?

The house has no basement. A neighbor said the company applied bitumen and then a slurry coat, and that would be sufficient. Additionally, we are installing the dimpled membrane, which should be more than enough.

Now I don’t know if the dimpled membrane was installed correctly, if the company really applied bitumen, and if everything we're doing is enough — or if we should call a specialist? Attached is a photo; I am totally confused. What do I need to do to protect my house from moisture and damage for the next 10 years? I don’t want to forget anything, as everyone says something different: One road construction worker offers to do it for 150 euros, saying he will remove the gravel, apply the slurry coat, and install the dimpled membrane with the dimples facing the wall. Another person says it would cost 5,000 euros and that there needs to be insulation, then a layer – I don’t know what exactly – then styrofoam, and then the dimpled membrane with drainage.

I am confused.

Exterior wall with illuminated window, curtains visible, gravel ground and black drainage mat.

Bauherrin12322 Jun 2025 15:42

Teimo1988 schrieb:

Yes, that looks quite good. However, I would install the dimple membrane with the dimples facing the wall, or buy a dimple membrane with fleece and then install it with the fleece side against the wall.

Thank you very much for the information. I need to ask more precisely now: what exactly has been done well? I can’t make sense of the pictures either.

Bauherrin12322 Jun 2025 20:44

So, someone came by today to take a look. He said that the pictures show only a bitumen coating, not a bitumen membrane. That means it would be better to install the membrane as well...

Teimo198822 Jun 2025 20:50

I’m not very familiar with aerated concrete. It’s uncommon in our region. If it were clay blocks, I wouldn’t add anything else on top. However, aerated concrete is obviously problematic if it gets wet. Maybe someone with more experience with aerated concrete can chime in.

nordanney22 Jun 2025 21:09

#10

Bauherrin123 schrieb:

So, someone came by today to take a look, and they said the pictures show only a bitumen coating, not a bitumen membrane. That means it would be better to install the membrane as well...

Of course, if you go to Mercedes after driving a VW, the salesperson will say "a Benz is definitely better." The next stop would be Bentley with the Benz. What do you think they would say?
Sure, many things are better. But if someone says your house could be better, would you then sell it?
A bitumen coating or rather a KMB (liquid applied waterproofing) is good and works well.

However, you haven’t commented yet on the window sealing. I find that much more important than the question of coating versus membrane.

What did your building expert say, the one who has been overseeing the construction for you?

Bauherrin12322 Jun 2025 23:03

#11

nordanney schrieb:

Sure, if you go to Mercedes after driving a VW, the salesperson says, "a Mercedes is definitely better." The next stop with the Mercedes is Bentley. What do you think they say?
Of course, many things are better. If someone says, your house could be better, would you sell it then?
Bitumen coating or rather KMB is good and it works.

But you haven’t commented yet on the window sealing. I think that is much more important than the question of coating or membrane.

What did your building expert say, the one overseeing the construction for you?

Hello and thank you very much for your reply.

The building expert will only respond tomorrow, as there hasn’t been an answer yet. I can’t say anything about the windows because I’m unsure; I thought it was done correctly. I have no plans for it—what exactly needs to be done? If you notice something I’m overlooking, for example why it is more important, please share that information.

Sure, Mercedes is better than VW and so on, but I don’t want to have a breakdown if the car leaks because I didn’t seal the windows properly and moisture comes in. It doesn’t matter which car it is; the windows have to be sealed. So if my house is sealed well, that’s fine, but if something MUST be done I don’t want to save money in the wrong place.

Have I been told that Poron concrete must be done? Honestly, after construction I have no energy left and can’t even remember many details; I have forgotten a lot.

So, my question to you: Please give me TIPS on what I need to pay attention to and what you think must be done. In which order…

nordanney22 Jun 2025 23:28

#12

Bauherrin123 schrieb:

If you notice anything I might be overlooking, for example why this is important, please share the info.

You can’t see anything. That’s why I’m thinking this through. The KMB waterproofing is fine. So, only the door remains.

Bauherrin123 schrieb:

Please give some TIPS on everything I need to consider and what you think must be done. In which order…

1. Ask the expert (what did they do during the construction?)
2. Check if the door was properly sealed (this also relates to point 1.)
3. Install a dimpled membrane against the wall.
4. Backfill and landscape the garden.

ᐅ Concrete slab and house protected against moisture with dimpled membrane? Any experiences?

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