Cellar Sump Pump

[Nathan90]

Hi All,

So here’s the situation…

Older property with a cellar, built late 1800’s. There was (judging by the neighbours property) a drain from the cellar into the city drains, however an extension has been built capping this off.

There is a drain from the front of the house that runs into the cellar, straight into a hole just dug into the clay with a sump pump. The front of the house is raised about 6ft from street level.

Water comes from this drain into the hole and I can also see water coming through the stepped foundation. This only happens when there has been rain - hot summer hole dries up and is left with around 1 inch of water.

My plan -

1. Core drill some holes into the front wall of the garden - I’m assuming that there is nowhere for rainwater to drain away from the house so it’s taking the path of least resistance which is into the cellar.

2. Put in a proper sump pit - Dig out a sufficiently sized hole, place a 900x600 concrete paving slab at the bottom and build a pit on the slab out of 440x100x215 concrete blocks three courses deep which will give me a pit depth of 645. I’ll then backfill the hole around the box with stone and add an inspection cover.

I’m keen to get some opinions from people on here about the above…

 

[Nathan90]

Sorry is there anyone who can comment on this?

 

[Madrab]

Very hard to comment on a given the situation. Obviously the original engineers got it right by creating a through run for the excess water that hit the impermeable layer (clay) that runs into the cellar, to then allow it to run through to the sewer. Could a new run through the the sewer, bypassing the extension, not be laid?

Constructing a sump would usually follow normal design standards, loads of them online but whether it would be adequate for your situation would be down to local site conditions, unfortunately not something that can really be gauged remotely online.

That being said if the current approach is adequate then formalising that using a proper sump design would be the correct approach. One thing I would consider though is to build extra capacity into whatever is being laid to ensure it wouldn't be overwhelmed.

 

[Nathan90]

Very hard to comment on a given the situation. Obviously the original engineers got it right by creating a through run for the excess water that hit the impermeable layer (clay) that runs into the cellar, to then allow it to run through to the sewer. Could a new run through the the sewer, bypassing the extension, not be laid?

Constructing a sump would usually follow normal design standards, loads of them online but whether it would be adequate for your situation would be down to local site conditions, unfortunately not something that can really be gauged remotely online.

That being said if the current approach is adequate then formalising that using a proper sump design would be the correct approach. One thing I would consider though is to build extra capacity into whatever is being laid to ensure it wouldn't be overwhelmed.

Thanks Madrab…

It wouldn’t be possible to bypass the extension without serious work.

I would say the current set up is adequate although there is no resilience should something fail.

It’s more of a question if my idea of a brick built pit will do the job or I should buy an overpriced sump basin

 

[just pumps]

If you fit a pump have you plans for the outlet hose?

 

[Nathan90]

If you fit a pump have you plans for the outlet hose?

There’s an existing sump pump in place, I’ll just be replacing this with the outlet going into a drain.

 

[Nathan90]

If you fit a pump have you plans for the outlet hose?

What are your thoughts on a brick sump pit?

 

[Madrab]

As long as the sump is created properly and watertight etc then nothing wrong with constructing a brick built one IMO. Only thing I would consider that if you are getting permeation through the founds then whatever side that is on may need to be left porous to allow that water to filter into the sump.

 

[just pumps]

What are your thoughts on a brick sump pit?

Same as Madrab above.

 

[Nathan90]

As long as the sump is created properly and watertight etc then nothing wrong with constructing a brick built one IMO. Only thing I would consider that if you are getting permeation through the founds then whatever side that is on may need to be left porous to allow that water to filter into the sump.

Amazing, I am getting water through the foundation and that was my plan! Much appreciated!