1

I have a basement wall made of block/poured concrete, but it's leaking. My plan is to install a French drain to take care of the leaks and prevent flooding.

To complicate matters, this wall isn't vertical, so I had to shore it up with a load bearing 2x6 stud wall when I rebuilt the floor system above. This new 2x6 wall was engineer approved as part of the floor renovation.

I'd like to replace this stud wall with some other sort of support so I can get rid of it permanently, then dig the drain system to take care of the leaks.

Here is a picture showing an overview of the room. This is a closeup of the the wall, top plate and joists: enter image description here

Note: question updated to include information buried in the comments, so some comments may not make sense anymore.

12
  • 2
    Are you sure those studs are actually load bearing? That would be an unusual configuration, unless they were put in to shore up the structure. If that's the case I'd be really reticent to mess with it!
    – GdD
    May 26 '20 at 17:09
  • I agree with GdD, those joist must be sitting on the concrete wall. You can drill a small hole in the blocking between two joist's and take a peek in with a flashlight. you build that wall ? if not why do you think the wall is doing the load bearing ? The studs are not directly under the joists. More info is needed.
    – Alaska Man
    May 26 '20 at 18:01
  • 1
    You've posed an XY problem. Please revise to explain what you're actually trying to accomplish. I assume that you simply want to box around your window with the energy wall, but you need to tell us that.
    – isherwood
    May 26 '20 at 18:23
  • @AlaskaMan, studs need not be directly below joists. In fact, it's rare that they are.
    – isherwood
    May 26 '20 at 18:25
  • 1
    @TonySmith If the wall is doing the load bearing then you would need a big a$$ wood beam or a steel beam to replace it but it would still need to be supported. . You need an engineer. Steel beam 4 feet in from the wall ?? Maybe fix the leaking wall first.
    – Alaska Man
    May 26 '20 at 18:37
2

There are a few issues here: 1) existing exterior concrete wall leaning, 2) location of French drain, 3) new wood wall installed to help existing concrete wall, 4) engineer designed,

  1. If the exterior wall is leaning in, it could be dangerous. If there are no cracks on the inside of the wall, then it’s probably not in danger of immediate collapse. However, that pressure is probably due to earth and moisture pressure on the wall and needs to be eliminated.

  2. In order to eliminate this pressure you’ll need to install a french drain on the exterior of the wall. (Some people have suggested a drain be installed between the concrete wall and the studs inside. This is not acceptable.)

Water flows in the direction of least resistance.

Moisture is either coming up from below (a rising water table) or its coming from the surrounding ground water in the saturated soil, or both.

If it comes up from a rising water table, it will enter the living space from below through the crack between the foundation wall and slab.

If it comes from the surrounding ground water, it COULD enter the living space through the wall, especially if the EXTERIOR side of the foundation wall is not sealed properly.

Either way the moisture enters the living space it will need to be collected and disposed. I think the best way to collect it is on the exterior side of the foundation wall in drainrock and a perf pipe laid 6”-8” below the interior basement slab.

To keep the subsurface water from seeping through the wall, I recommend installing a moisture barrier on the exterior side of the foundation wall and install a 2” thick plastic mesh on the wall to allow water to flow down to the perf pipe. If dirt is allowed to be backfilled against the wall, the dirt could hold the moisture giving it a chance to seep through the wall.

Once collected it needs to be disposed by extending a solid pipe over an embankment or in a collection well and pumped away.

This may be the most expensive method of solving the problem, but it’s sure to work.

  1. You mention that the new wood wall was installed to help the leaning concrete wall. I hope your engineer didn’t come up with that idea. The Code does not allow wood to support structural concrete.

  2. You keep referencing an engineer that helped you. I doubt he’s an engineer and I’m certain he’s not a structural engineer. I’d recommend you use a structural engineer (not a civil engineer) or architect that has experience in residential construction.

Side Note: That wood wall does not have a header over the window. How can the wood wall support the floor joists above without a header? Did your engineer design that?

1
  • Just a note that the question as it now reads is based on my interpretation and compilation of the comments on the OP. I may have misinterpreted something. I hope OP will come back and review my edits (I did ask) to ensure that I got it right. Nothing wrong with your answer, just tempering you indictment of the "engineer" with the fact that I may have gotten it wrong.
    – FreeMan
    Jun 26 '20 at 16:46
0

First that is one very interesting wall. Between the tube, the switched outlet feet in the air and the plumbing lines... completely distracts you from what seems to be a really poor support wall.

Let's just stick to the facts of you need to install a french drain...

You are going to have to build a temp wall a few feet over and carry the load from that point. It really is the only way of doing it. It is temporary so you could get by with some 2x4s and a few jacks but honestly if it were a basement that I was redoing I would just build a wall to spec so that I could transfer that wall to another location once I am framing out the rest.

1
  • LOL. That switch was in a secret room I build for a kid living with me. It was hidden behind a chalkboard. Yeah, I am starting to think that now might be a good time to do it "right". God forbid that basement pad ever heave...I'd lose a bedroom. Funny though that I had a licensed engineer say that it was okay.
    – Tony Smith
    May 26 '20 at 19:00
0

I think the short answer is this: you can't modify that load bearing wall to accommodate an interior French drain.

The whole situation is sketchy to begin with as others have well described. Consider that a load bearing wall must transmit its load to a footing, when then transmits the load to the soil. Where is the footing? It's under the concrete wall. It's not under the floor slab. Well, they do overlap a few inches.. but where does an interior French drain go? Around the perimeter -- one cuts the floor slab around the edge, making a gap between the slab and the foundation wall. This means what little overlap there is between floor slab and footing would be made even smaller, and this makes the sketchy bearing-without-footing situation even worse.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.