Hello experts,
I have a problem with the revision shaft in our house (built in 1966). Probably due to the current weather (frozen ground and heavy rain), I have water pressure in the shaft. The shaft in the basement is about 70 cm (28 inches) deep and measures 50 cm by 100 cm (20 by 40 inches). At the bottom lies the main sewer line with a backflow valve (this is relatively new, functioning properly, and fully permeable, I have checked). The pipe rests on gravel, and beneath that is just soil.
Two days ago, the shaft was almost completely filled, which caused water to leak into the basement area at a slightly lower level, exactly where the pipe runs underneath.
It appears, and most likely is the case, that water pressed up into the shaft from below. The shaft is also very close to the exterior wall (front garden, then the street). I was advised to pour concrete or screed on the bottom of the shaft (the walls are concrete) in the floor area as well. For this, I would need to remove the gravel and then apply the material directly onto the concrete. My question is, would you also recommend using concrete/simple screed or something else? Perhaps a bitumen membrane first on the underside? These weather conditions (saturated soil) are rare, but I am considering purchasing a submersible pump for the shaft just in case. Of course, the drainage in this area is not ideal, but I want to avoid digging up the area. Behind the shaft (towards the house) the ground slopes downhill, so water does not push against the exterior wall. In front of the house, the street is relatively level with a slight slope away from the house.
Thank you for your opinions and tips.
Best regards, Andrew
I have a problem with the revision shaft in our house (built in 1966). Probably due to the current weather (frozen ground and heavy rain), I have water pressure in the shaft. The shaft in the basement is about 70 cm (28 inches) deep and measures 50 cm by 100 cm (20 by 40 inches). At the bottom lies the main sewer line with a backflow valve (this is relatively new, functioning properly, and fully permeable, I have checked). The pipe rests on gravel, and beneath that is just soil.
Two days ago, the shaft was almost completely filled, which caused water to leak into the basement area at a slightly lower level, exactly where the pipe runs underneath.
It appears, and most likely is the case, that water pressed up into the shaft from below. The shaft is also very close to the exterior wall (front garden, then the street). I was advised to pour concrete or screed on the bottom of the shaft (the walls are concrete) in the floor area as well. For this, I would need to remove the gravel and then apply the material directly onto the concrete. My question is, would you also recommend using concrete/simple screed or something else? Perhaps a bitumen membrane first on the underside? These weather conditions (saturated soil) are rare, but I am considering purchasing a submersible pump for the shaft just in case. Of course, the drainage in this area is not ideal, but I want to avoid digging up the area. Behind the shaft (towards the house) the ground slopes downhill, so water does not push against the exterior wall. In front of the house, the street is relatively level with a slight slope away from the house.
Thank you for your opinions and tips.
Best regards, Andrew
Hi,
using a submersible pump is definitely a good idea, but it won’t help if you’re not around. Ideally, you should have one that starts automatically when water rises in the shaft. We sealed our basement windows, so no matter how much water enters the shaft, it won’t get inside.
by
using a submersible pump is definitely a good idea, but it won’t help if you’re not around. Ideally, you should have one that starts automatically when water rises in the shaft. We sealed our basement windows, so no matter how much water enters the shaft, it won’t get inside.
by
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