So a few friends and me have this really cool location we intend

Look up 'basement waterproofing' on Google.

There are many functional options, and yours isn't one of them.

>>1169548
Doesnt sound right to me. Exactly how much concrete will that work out (size of wall x depth of cavity). You dont see that many poured concrete walls, they are usually prefabricated if so. We just did a huge pour in an above ground canal but it was only 4 foot by 4 foot.

Can you stop the water at the other side of the wall or is it a cave?

Where is the water coming from, just hiding it behind a new wall sounds a bit of a temporary fix.

dig out existing ground outside wall
install drain
waterproof wall on outside
fill back in

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>>1169576
The long wall (pic related) is about 16 meters long, and 3 meters tall. Behind the wall is a mound, or just "ground". In my mind I was looking at a thickness of 5-10 centimeters, which equates to between 2.5 and 5 cubic meters.

It sure is quite the investment relatively speaking, but if it turns out it's an all-out bad idea, it's also a waste of time and money I guess.

The water is combing trough the wall, as best i can tell. (see pic) - the new wall would aim to block that, but it wouldn't be a part of the carrying structure.

As for digging out the outside of the wall and waterproofing it: the property owner has shown some reluctance to the idea, and projects (even good solutions) moves kind of slowly.

(see pic in post: it's cut across the short side)

To summarize; the hope was to achive one: keep water outside the room itself, and two; provide a flat surface for mounting shelves and workbenches.

>>1169578
Thanks, good advice I guess. Will look into if this can be done.

>>1169591
I wasnt really thinking about wasting money, more about the weight of the wall and your safety.

Suppose you could run a drain along the bottom of the wall, cover the wall in a thick waterproof membrane and then do your wall idea. Just perhaps pay attention to the wall anchors if they rust through in a few years the whole new concrete wall may become free standing and collapse in wards squashing anyone in its way?

>>1169591
>Will look into if this can be done.
thats what you have to do. no amount of interior waterproofing or extra concrete is going to hold back that hydrostatic pressure. if you want dry walls, you dig that shit out, put down drain tile, and slop that exterior wall with urethane and a layer of 8 mil plastic.

>>1169591
Concrete is not waterproof. Also, if you have a moisture issue in a basement, covering it is the last thing you want to do, because lack of airflow to evaporate and disturb = huge mold growth. is the issue you have damp walls, or is there always puddles on the floor?

Is it constant, or only when it rains? if it's only when there's rain, then it's not the water table, it's rainwater being directed to pool against the wall underground, and you can fix it with landscaping.
The easiest way would be to dig out like .5m? along the wall, tamp, and smooth the dirt, put down painters drop cloths on a shallow slope away from the wall, carefully add enough dirt to weight it down so it doesn't bunch or move, then refill with the dirt you previously removed. The water should sink through the dirt and be directed away from the house. you can do this just by tamping/ shifting the dirt slope if you have clay heavy soil which won't absorb the water.

Commercially waterproofing a basement by digging it out and waterproofing sections of the exterior and adding drains is on the order of $20k-30k for a house, so yeah, not a small endeavor.
A new system is to use a machine to inject clay against the walls, and costs only about $5k, but I haven't seen much in the way of reviews.

Honestly, I would suggest building tool walls/shelves anchored by workbenches sticking out every few feet/In an L shape, and just leave a few inches between them and the walls so air can flow and evaporate.
If you can't fix damp floor, then just put everything on the solid cinderblocks or plastic bed riser type things. Rubber chair feet? Unless the basement actually floods regularly, that should solve your problem with it.

>>1169591
your picture doesn't give a good idea of the conditions. If it's open to the sky, the issue is probably condensation as much as seepage.
Is the long wall the only one that has seepage? are you sure that none is coming up from the floor?

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>>1170192
Sorry about filesize. I am fairly certain the water is coming through the long wall (to the right in the picture), and its only when it's raining water seeps trough.

The property owner believes that rain which collects on the roof then flows down the wall and into the room.

As for digging out the backside, there is further concern that the wall may give and collapse. It was dug up about a year ago and drained. But he didn't dig any closer than 2-3 meters from the wall, and I don't know how deep he dug.

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>>1170461
Here is the opposite side. It's these two which leaks during rain.

The roof, as you can see, is flat. But it's fairly new, so it doesn't leak. We are planning to build a roof with considerably overhang over the walls.

1. Excavate the earth next to the foundation
2. Lay gravel
3. Installing perimeter drains
4. Applying a polymer waterproofing membrane
5. Back fill

>>1170461
>The property owner believes that rain which collects on the roof then flows down the wall and into the room.
>We are planning to build a roof with considerably overhang over the walls
It seems like that's where you'd wand to start then. Shed the water properly, then see how the wall does.