Basement Water Intrusion

[Yakman256]

Hey all,

This question is actually for me and my house where I’m trying to resolve some water intrusion issues in my basement due to high groundwater. On one side of the house I have an addition supported by brick columns that do not go down as far as the basement footing. I have already diverted the surface water away from the house and that helped but I still have water intrusion through the cinder block walls when the groundwater raises.

I would love to excavate under the addition and apply a waterproofing membrane but there is a whole host of safety issues associated with this and I’m looking for an alternate solution. I’m considering only having the voids within the block walls pressure grouted but I don’t know much about it. I’ve also read about pumping a bentonite slurry though the wall onto the Wall/Soil interface but I would prefer not to put any additional lateral pressure on the wall when the bentonite reacts with the water.

Any ideas?

 

[engineered2005]

I assume you have a poured slab floor...have you considered a gutter system along base of the wall (a few inches deep) to collect and convey to your sump pump pit? Have you looked into a waterproofing paint also?

Brian|PA EIT|Civil-Highway Engineer
Consulting Southcentral PA
PSU 2009|BS Civil

 

[Yakman256]

I actually have an interior perimeter drain under the slab already and the basement wall has a coating of waterproof paint. The hydostatic pressure is so great that the water just seeps through the block. My other concern is that if the water seeping through the block it will degrade the block over time which is why I thought of the pressure grouting.

 

[bridgebuster]

Can you put in an interceptor pipe? It would be away from the house, but it might be able to convey some water away. How old is the house. Old cinder block, as opposed to concrete block, will eventually crumble due to leakage.

Grouting the wall might work; it'll be a pain in the @$$ with having to fill every cell. You could try soil grouting; might want to repost the question in the foundation engineering forum.

 

[msquared48]

I would look to trying to locally lower the water table around the house if at all possible.

Mike McCann
MMC Engineering

 

[Yakman256]

Bridgebuster - I thought the same thing about the degradation of the block due to leakage. That's another thing I thought the pressure grouting would help resolve.

My Thought was that if I pressure grout the walls and I install the exterior perimeter drains at the other three sides of the house the water would pass to the perimeter drains on the sides of the house rather than through the house or at least reducing the hydrostatic pressure to a point where the leakage is no longer a problem.

I will post this on the foundation forum and give the Dirt guys a crack at it.

Thanks for all our responses.