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How to stop rainwater coming through downstairs block wall?

Hi, for many years we have had water pooling on a path alongside our downstairs block wall. The room inside the wall is situated lower than the path, and over time we have started getting paint bubbling on the inside of the concrete block in the downstairs lounge & some discolouration of the carpet, though it’s not wet. So, yes, water Esme from

the outside, but is there anything we can do with the inside to help waterproof it from there, rather than dig the whole outside concrete path up? Suspect this has been happening for 20 years. Cheers Si

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EricL

Hello @monwinter

Welcome to the Bunnings Workshop community. It's sensational to have you join us and thanks for sharing your question about your block wall.

The issue with sealing the wall from inside is that water will then start to gather inside the wall itself. The water will start spreading inside the wall and it will look for the easiest points of entry. It will spread wider and bigger until the wall is totally saturated. The best solution is to seal it from the outside. Any sealer placed at the back of the wall is in danger of being pushed off by the water inside the wall, this is why you get the bubbling paint.

I understand that you are not keen to dig the concrete path, but this is the only way to seal the wall properly and prevent water from going through it. One other possible option is to correct the fall of the concrete path and have water flow away from the house. However, in large deluge there is still the possibility of water getting through. I propose getting a quote from a handy person on how much it will cost to dig the concrete path and painting the wall outside.

Just in case you were wondering what paint would be used outside under the ground a good example would be the - Gripset Betta 4L Bitumen Rubber Waterproofing Membrane. This will seal your wall properly and prevent water from coming through.

Let me call on our experienced members @Dave-1 and @Nailbag for their recommendations.

If you need further assistance, please let us know.

Eric

Dave-1

Good Evening @monwinter

@EricL has described it well. 😕 I had a similar issue and yeah the solution was dig out the area and seal it and for me I also left the area exposed to air. I didnt not want water entering my garage/libary 🙂

Fixing water ingress issues in garage and Gabion Wall to stop water ingress to garage Show the steps I went through.

Having the water run away from the area is good. Subsurface water tho still will bank up behind the wall. Its amazing how water will find the easiest path to go downhill 😕

As a temporary fix, you could up the airflow against the wall or in that section of the hall so teh wall itself dries easier. You say 20 years which sounds like it has lasted a long time, maybe remove the paint on the wall and increase the airflow? Is there a chance of a photo of the area?

Dave

Nailbag

Hi @monwinter

Two thoughts here. The first is to cut a trench through the concrete path along the wall and install a grated drain system to the storm water to take away all the water. The 2nd and more involved and expensive would be to lift the low areas of pathway and replace it with a new graded sections that falls away from the house path. I would be inclined to go with option 1 that should get you sorted without any waterproofing.

Nailbag

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