Sump Pump

[Herefordian]

Hi all,
We are considering a sump pump for our damp (& wet when the water table rises) cellar. It is now flooding (from a few mm to a few cm) coming up through tthe floor. A previous owner concreted over the floor, so will need to dig down. Have tried a normal surface pump, but that doesn't really help apart from some of the worst of it.
We are considering a "Basement Sytems" sump pump & Waterguard system.
Bearing in mind the cellar is mid C18, would putting a pump in cause any problems do you think?
Many thanks in advance!

 

[Penners]

Hmmm... the following answer has no basis in expert knowledge.

I think the first concern should be: what sort of subsoil do you stand on? If it's clay, then you need to proceed cautiously for fear of drying out the clay and causing subsidence. This principle may also apply to other types of subsoil.

A porous sump or pit fitted with an immersible, float-actuated pump, may indeed be a good solution to your problem, but if I were in your shoes I think I would want the advice of a structural or geological engineer before I proceeded.

 

[MatthewC]

Our church has had a sump pump for years and it works quite well at keeping the water level down, although the cellar remained quite damp. The pipe outflow goes up to a bit of drain pipe which leads into a french drain - then I realized recently that, when the pump operates, water was coming back out of this drain pipe which must therefore be blocked. So I diverted the outflow pipe to a rainwater gully (which is NOT blocked) and the cellar has since dried out considerably. Presumably it had been re-circulating the same water...!!

 

[Neetie]

Hello,
We just purchased a house with a wet cellar. There is an old soakaway linked to a short well/bricked chamber in the floor which has since had a sump fitted though the floor remains wet. I just wondered what you did and how dry your cellar now is? We've had a couple of companies look but none suggest the same things which makes it's hard to know what is best, we don't know whether or not to block the existing soakaway and chamber and most companies recommend full blown waterproofing which is beyond our affordability. Thanks.

 

[Feltwell]

On what is a very old thread, you're probably better off sending the OP a private message - that way they get an email if they're still using the same email address. Herefordian doesn't ring any bells as a recent contributor.

"full blown waterproofing" can cause other problems. Cellars just aren't really a habitable room. Ours has a freezer down there (which doesn't mind the damp) and lots of junk. Good for storing paint tins, it never freezes!

 

[CliffordPope]

Good for storing paint tins, it never freezes!

Yes, I've got a large collection of very rusty paint tins too, many are welded to the shelf where the paint leaked out years ago.

 

[Feltwell]

Good for storing paint tins, it never freezes!

Yes, I've got a large collection of very rusty paint tins too, many are welded to the shelf where the paint leaked out years ago.

You must be very proud - have you had the collection valued? :lol:

Perhaps not environmentally as good, but plastic "tins" are a damn sight better!

 

[LadyArowana]

You must be very proud - have you had the collection valued? :lol:

Perhaps not environmentally as good, but plastic "tins" are a damn sight better!

I never thought of that, just took a whole bunch of ancient tins to the local recycling centre, £££ wasted dammit

 

[88v8]

....the floor remains wet

So what does the soakaway do? Is it supposed to be draining the cellar?
Just digging a hole or installing a pump won't dry the floor.
The water has to be purposefully collected.

Our cellar had some £££ damp-proofing done by the PO, but not under the stone stairs which were sopping wet.

We had the stairs taken out for repair, and installed a 4" perforated pipe around the perimeter of the stairwell. This collects the water that runs into the stairwell from springs or external clay land drains and takes it into a sump, whence a pump periodically evicts it. The (plastic) 25 gallon sump and pump came as a package. I think they cost about £3k installed.

Note also that sump pumps depend on a float valve, and float valves do not like dirty water. So the perforated drain is wrapped in Terram, and the water empties into a stilling basin - I used an old drinks bottle - to trap the sediment. Otherwise, the float jams and the pump doesn't operate and one comes down in the morning to a lake.

The cellar is dryish. But it's probably had >£10k spent on it. And we have a dehumidifier down there running 24/7.

As Feltwell says, cellars were not designed as habitable spaces.

Ivor

 

[Feltwell]

And we have a dehumidifier down there running 24/7.

I did that for a bit, then I had a bit of a rethink as it occurred to me is that all I was doing was drying out the surface of the walls - the damp is coming from the soil behind, through the brick, so chances are 95% of the brick is still damp and all the dehumidifier is doing is pulling more damp through - a never ending cycle.

 

[Flyfisher]

Absolutely. A dehumidifier will never completely dry out a cellar . . . in the same way that a heat pump will never refrigerate the practically unlimited supply of heat from the air/ground/water it's using.

So why do I also run a dehumidifer in our cellar for about nine months of the year? Because it keeps the air drier and there is no longer almost constant condensation on the floor joists and boards that form the ceiling of the cellar, which led to historical rot and some rather clumsy repairs.

 

[88v8]

...all the dehumidifier is doing is pulling more damp through - a never ending cycle.

Yes, but it keeps the snails and mould at bay.

And funny you should mention that, PO had an exercise bike down there.

Ivor

 

[CliffordPope]

all the dehumidifier is doing is pulling more damp through - a never ending cycle.

Isn't that what a sump pump does?
Like pumping water out of a well.

 

[Feltwell]

True - stops you needing to wear waders to get into your cellar though!

I'm lucky here in that although the cellar is damp it doesn't usually flood. It did so once to a depth of about 3", but I can't complain as that was during extreme wet weather when houses not far away flooded on the ground floor. I was down there at midnight lifting my freezer onto old pallets! The only long term action I took was to build a platform for the freezer about 9" off the floor, from bricks and paving slabs, which of course has ensured it's never flooded in the 10 years since...….

The roof on mine is an iron beam and concrete, so no timber rot issues from condensation.