basement drainage channel

[Jules Richardson]

So, my north-facing basement wall leaks a bit due to natural slope of the land and 60-odd years of deterioration to whatever coating and drainage might be on the external side of the wall - but it'll get particularly bad in about a month as things warm up and the snow we've got here (currently around 18" deep) melts. (By 'bad" it's not horrible, but enough to end up with a couple of puddles and musty rooms, preventing the space from being made more habitable)

The plan has always been to see if I can't make a drainage channel on the interior side of the wall (the basement has a concrete floor) which will direct any water ingress to one end, where there's an unfinished section of floor about 3'x3'. I can dig down and put a tub in that unfinished section, and I have a sewer pump which can sit in it and pump accumulated water out - although initially just directing water into the sandy dirt will probably do and allow it to soak away naturally.

Anyway - thoughts on the best way to do this? I was thinking about pouring concrete between a couple of forms to create a 'wall' about 3.5" wide and 3" high, but will new concrete likely adhere to the old OK, or should I be thinking about scoring the old concrete to provide a better key? Also, is treatment of the channel using some kind of rubberised product wise, or will 3" of concrete form a natural barrier without (as long as it doesn't ever crack)? I'd like this to last at least 50 years, after which I won't be around to care :-)

If I do the 'wall' approach then the plan will be eventually to put a false wall on top extending up to ceiling height (leaving a 1-2" gap between it and the real basement wall behind), but for now I think I'd just embed some J-bolts or concrete anchors into things (letting them penetrate down below the concrete floor level) and leave that project for another day.

Cheers,

Jules

[Andy Burns]

Could be worse, 18' deep in parts of Japan.

[Andrew Mawson]

Can you not stop it coming in by excavating on the outside of the wall and putting in a french drain and land drain?

AWEM

[Harry Bloomfield]

Jules Richardson pretended :

One building I worked in had to have something similar done. They used galvanised 3" x 3" angle, bolted to the floor with a bed of mastic under it to seal it. It was quite effective.

[Martin Brown]

I would be more inclined to prevent ingress of water by altering the exterior of the wall if possible rather than pumping it away internally after it has come through the wall.

Ideally you want any channel sloping down to the sump with a pump in.

[Jules Richardson]

In the grand scheme of things it'd be the right way to do it, I'm sure - but it would be a complete pig of a job. I've got a fence which meets the house part-way along, plus the well pipework and power to the workshop come through that wall - not to mention that I'd have to dig down to the footer, so 9' or so, which would require a mini digger. Plus of course it'd have to wait until all the snow's gone and the ground's thawed out.

Part of the problem too is that at the west end of the wall (which is at the lowest part of the outside slope) there's a wood chute into the basement; I did dig down around that last year and re-did a lot of the concrete, which helped enormously, but I think it'll always prevent good drainage outside.

cheers

Jules

[Jules Richardson]

That's an interesting idea. I wonder what the longevity will be like; my comment about a 50 year lifespan was due to my wanting to eventually put a false wall to ceiling height on top, so there wouldn't be access for maintenance - although having said that, I'm only intending the rooms down there to be utility space rather than living space, so I suppose I could use plywood for the wall covering which could in theory be unscrewed to provide access once every ten years (picking a number at random).

I need to stop by a couple of DIY places today anyway, so I'll take a look at what they have just to get an idea of prices.

cheers

Jules

[harry]

There are special systems for dealing with this problem. You could make your cellar habitable. Example here. But lots more out there.