Drainage channels and / or pump

[Silly Car]

We’ve got a small block paving area outside our bay window and front door which floods when it rains as it is below the level of the garden, heavy rain forces rain into the house through the floor (160 year old house with I suspect minimal DPC / tanking under the floor).

I’m considering digging out a trench in the block paving to install a drainage channel draining into a length of 4” pipe returning to the surface via a hopper.

Undoubtedly this will help with small downpours as I will have effectively created a subterranean tank with the pipework at a rate of 9.5l per metre of pipe plus whatever the channel holds.

The big question is how can I get the water out of a 4” pipe and into the French drain, 1m above and 2m down the garden? I cannot seem to find a suitable pump, either manually or automatically controlled? Thankfully, there is an outside socket nearby.

[maccecht]

Install an aco running into a small plastic manhole either 300 diameter or 450 diameter install an auto start sump pump then run the pipe from that to your nearest good drain loads of pumps on the market with float switches. You can even buy ready made small pump Chambers. Like everything how much do you want to spend
This sort of pump in a small chamber ready made plastic chamber or make your own. Bit of digging but peice of mind after that of no flooding. Plug it in check it every so often for silt job done. If you put the pump on a small pedestal inside the chamber it will last longer and you can clean any silt out annually.
https://www.anglianpumping.com/product/ ... itch-750w-

[Mussels]

Those pumps are common and cheap, I got one from Lidl that I use in the pool. Screwfix had them on display today so a few people probably have the same issue.
The float switch is a little vague so it might need to sit in a fairly big sump.

[Gregor]

What Maccecht says.

I’ve got a couple of sumps in my cellar, both with Draper pumps that have internal float switches.

The smaller is a SWP1255IFS 300w which has been in place for at least 10yrs and sits in a sump 270 wide x 340mm deep.







First year we moved into this house, we woke up christmas eve to the cellar slowly filling up with ground water after weeks of rain

I had a look at 12v marine bilge pumps which are a lot smaller but the use of a battery and maintenance was hassle, keep meaning to get one just in case of a power cut.

[Count Steer]

Don't go too cheap on the pump. I bought a submersible to pump water around from a water butt and the rubber waterproof sleeve where the power cable enters the pump body perished. Exactly not what you need when combining mains power and water! (It went in the bin). They really shouldn't sell stuff without proper double seals and that don't fail safe.

[Kneerly Down]

I have submersible, like the one above and bilge pumps, used for getting water into our hillside tank that feeds the house when the normal inlet freezes or fails.
I have to use a battery and inverter for the submersible, hence I prefer using the bilge pump as it's one less thing to lug up the hill.

Pros of the bilge pump are that it's much smaller and more efficient with power as it's going for flow with a max head of 2m, so if the lift isn't much it's working nicely within its range. It's also pretty quiet.
The submersible is bigger, heavier and much noisier. It is handy if I have a pipe that needs water forced through it to unblock it.
If the bilge pump can manage the amount of flow needed I'd be tempted to go that route....12V is easier to power come the zombie apocalypse!
Submersibles tend to be 300W-900W as opposed to sub 100W for a bilge pump...obv. pump less though.

https://www.ebay.co.uk/itm/142476892778
If 12V cables could be run from inside a £10 power adapter would do, otherwise a £20 IP67 adapter to the external mains supply.

The more conventional, and less hassle, would be to just use a submersible like the one above.
I'd definitely go for the integral float switch as the external ones can be temperamental.