Hello dear forum members,
we have purchased a house built in 1980 and noticed that when the groundwater level rises significantly, water enters at two or three spots where the basement floor and wall meet, which results in damp walls.
As far as I can tell, the basement floor and wall were poured up to a height of about 1.5m (5 feet). The masonry was applied only above that.
From the outside, it appears that there is a black waterproofing layer (as thin as paint) on the calcium silicate blocks, which I hope extends down to the foundation.
This summer, I plan to work on the waterproofing of the house walls and fully renew it.
My general question is: how can water penetrate into the interior in the area where the floor and wall (which seem to have been poured as one) meet?
I am a beginner and eager to do the work myself, so I appreciate any advice!
Best regards
we have purchased a house built in 1980 and noticed that when the groundwater level rises significantly, water enters at two or three spots where the basement floor and wall meet, which results in damp walls.
As far as I can tell, the basement floor and wall were poured up to a height of about 1.5m (5 feet). The masonry was applied only above that.
From the outside, it appears that there is a black waterproofing layer (as thin as paint) on the calcium silicate blocks, which I hope extends down to the foundation.
This summer, I plan to work on the waterproofing of the house walls and fully renew it.
My general question is: how can water penetrate into the interior in the area where the floor and wall (which seem to have been poured as one) meet?
I am a beginner and eager to do the work myself, so I appreciate any advice!
Best regards
HausiKlausi3 Mar 2020 21:24Sealing from the inside as an additional measure is pointless. You will still get water in, but it might not be able to escape anymore. A seal at the bottom only makes sense if it fully functions as an envelope. It is better to leave it as is and allow the ground the chance to release moisture again during heavy rainfall events.
Vicky Pedia3 Mar 2020 22:08Tamstar schrieb:
I had a project like that a while ago and wasn’t sure how to handle it... In the end, I didn’t have to make that decision What are you doing? It’s not your house? Sealing should generally be done from the outside!
HausiKlausi schrieb:
A waterproofing layer at the bottom only makes sense if it fully functions as an envelope. Otherwise, it’s better to leave it as is and allow the ground to dry out moisture during heavy rain events. Well, I want a dry basement, not one that lets the things I store down there get damp from below. The concrete slab itself isn’t necessarily affected by being moist.
Vicky Pedia schrieb:
Waterproof from the outside, generally! That’s difficult with a concrete slab or the foundations. That’s why the question arises whether to additionally interrupt the capillary action underneath.
HausiKlausi4 Mar 2020 09:32Tamstar schrieb:
Well, I want a dry basement and not one that lets the things I store down there get damp from below. The concrete slab doesn’t necessarily mind being wet.Well, I’m not so sure that’s what you want. I don’t want anything in the house that, hidden behind bitumen, I can only assume is still okay. First of all, I wouldn’t expect a 40-year-old concrete slab to just handle that without issues. Even small cracks plus moisture are enough to slowly but surely corrode the steel reinforcement under your
We also have a very old house. At first, it annoyed me that we occasionally had damp corners. I decided to accept that and adjust storage in the basement accordingly. It’s far from ideal, but retrofitting a reasonably economical waterproofing from below is almost impossible. Under no circumstances would I now take measures based on the “out of sight, out of mind” principle.
As I said, I wasn’t sure how to handle it, but to me, it seemed logical that you could seal off the interior.
The concrete slab is damp anyway, and with the dehumidification inside (which was intentional because paper was stored there—no need to debate the purpose of that :rolleyes), even more moisture was drawn in. In my case, the concrete slab was also unreinforced (poured) concrete, dating back to around 1910.
What you don’t see isn’t there and doesn’t really draw moisture, because the reinforcement in that case would simply rot away (there’s always some amount of moisture present when the slab is placed directly on the ground without a separating layer). The difference is that in this case, you can actually watch it happen.
Is your concrete slab now completely exposed without any covering?
The concrete slab is damp anyway, and with the dehumidification inside (which was intentional because paper was stored there—no need to debate the purpose of that :rolleyes), even more moisture was drawn in. In my case, the concrete slab was also unreinforced (poured) concrete, dating back to around 1910.
What you don’t see isn’t there and doesn’t really draw moisture, because the reinforcement in that case would simply rot away (there’s always some amount of moisture present when the slab is placed directly on the ground without a separating layer). The difference is that in this case, you can actually watch it happen.
Is your concrete slab now completely exposed without any covering?
HausiKlausi4 Mar 2020 10:04Tamstar schrieb:
Is your concrete slab now lying completely bare?Brickwork, which of course presents a somewhat different starting point. Moisture passes through the joints almost as quickly as it arrives. The basement has been dealing with this for over 100 years now. I couldn’t find any information in the existing plans, but it most likely just rests directly on the ground. It’s not constantly damp, but during heavy rain, groundwater or moisture particularly penetrates at the wall-to-floor junction.
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