How to build a water resisting retaining wall

[ihatesheds]

Afternoon all

So I decided (with the wifes' approval of course) to build my own outdoor kitchen.
Since we moved in I ripped out a load of overgrown bushes against the old (kinda) retaining wall that edges the 2 tiers of our garden. It curves a lot and is frankly pretty messy.
I use this space to house the BBQs, some equipment etc and honestly I've always wanted an outdoor spot to grill.

I'm still in planning mode but I have like 2.5m x 2.5 to play with and intend to make a |_| shape, it'll house some units from somewhere https://uk.vevor.com/outdoor-kitchen-door-c_10622, a sink, patio tiles as a floor etc. I will have to redo chunks of the wall to get the run to the nearest sewage pipe so I'm thinking it's time to fix all the breaks in it, repoint or even just rip it down and start again as it's an absolute mess in most places.

My biggest issue with what to do though is the carving into the existing garden.
Taking the wall out, and rebuilding it is easy enough...but what do I do about the water that runs through it all now. When it's hammering it down you can see the water leaking out of the existing walls.

If I just build a set of stone or wood cabinets into the mud, I'm going to clearly have a water issue where everything inside will end up covered in mould/wet all the time.

I think I might need to build a french drain round the side of the wall. Build a retaining wall in something like dense blocks, then a waterproof membrane and then build my kitchen on the other side of it?

I'm not even sure of exactly what I need to google/youtube to learn either so here I am looking for advice!

Thanks in advance

 

[DAZB]

You will need to excavate further back than the area you need and install some form of drainage to cope with water from the garden. In essence you remove a large % of it before it gets to the wall and if you search "retaining wall drainage" it will tell you how to go about it. You can reinstate a wall in any finish you like once the drainage is built and Gabion baskets are a nice visual effect and come in many sizes so worth a thought. You could even build in an Aco drain flush with the paving at the foot of the wall as an extra barrier and drain it off to where the land drain goes too.

 

[ihatesheds]

You will need to excavate further back than the area you need and install some form of drainage to cope with water from the garden. In essence you remove a large % of it before it gets to the wall and if you search "retaining wall drainage" it will tell you how to go about it. You can reinstate a wall in any finish you like once the drainage is built and Gabion baskets are a nice visual effect and come in many sizes so worth a thought. You could even build in an Aco drain flush with the paving at the foot of the wall as an extra barrier and drain it off to where the land drain goes too.

Thank you I will get googling!
I thought I'd end up cutting back further than just the kitchen

 

[^woody^]

If you like blue bricks or can tolerate red engineers, your problem is sorted.

 

[ihatesheds]

If you like blue bricks or can tolerate red engineers, your problem is sorted.

How so? I can happily put them as the main wall into the earth and do nicer on the sides we'll see.

 

[Cheslea2010]

I have seen many outdoor kitchens using gabion baskets to create the units and also to support bbq's, sinks etc. They look great and tend to blend in more with the garden. Gabion Baskets have come a long way from the old chicken wire type boxes they used to be. There are all sorts of planters, benches, fences etc that can be constructed from gabions.

 

[ihatesheds]

I'll take a look, but surely that'll just let water run through them to the cabinets inside?

 

[Cheslea2010]

The cupboards you use for outdoor kitchens are usually stainless steel and include the carcass. In effect a stainless steel box which would sit inside the gabion basket.

 

[^woody^]

How so? I can happily put them as the main wall into the earth and do nicer on the sides we'll see.

Because Class A engineering brick (Blue or Red), have a very low water absorption, and built in a suitable mortar and wall thickness, they will effectively prevent water soaking through.

Otherwise, you'll need to line the ground-facing side of a wall with polythene.

You mention "wood cabinets", but be aware that any timber will be prone to dampness when outside, regardless of what wall you build.