Stairwell Wall Leaning In

Hello DIY Folks. I have returned for more help but I'm not sure I'm in the right forum.
I have a walk-down to my basement that is framed by 6 x 6 timbers stacked up about 15 high. One of the sides is starting to lean in a few inches almost certainly due to poor grading and resulting hydrostatic pressure. I am in the process of excavating and regrading and, I'm almost done with the digging. But, I don't really have a good idea of what to do once I get down there. Merely relieving the pressure on the wall won't make it stand back straight again. I was thinking of attaching a sheet of plywood to it and using a sledge hammer to convince it to stand up straight but that seems a bit barbaric and unimaginative. Any suggestions? Photos attached. Please, no disparaging remarks about the color of the siding :-).

Almost done digging. Maybe three feet more.



It's about 1 1/2 inches off at the top.

Back in line by the sixth timber.

 

That structure will always have issues, now or in the future.

Google dead man anchors. At a min that needs to be installed, angling them outward will help but that would mean a total dis/re-assembly.

If you have room the best solution would be to terrace the grade and use something like boulders to hold the earth back, if they move a bit you wont see them as obviously as a flat wall.

 

The soil looks a little bit like clay (expands when it gets wet) so if that's the case I'd suggest you only use it as topsoil... not for backfill.

As for spreading the walls, build a temporary wall across the stairs. Lay a bottle jack on its side on top of that wall. Then block in front of and behind the bottle jack with some 4x4s or something, laying those pieces on the top plate as well. Once you remove the backfill you will be able to push it back into shape with the bottle jack. Move the wall and jack around as needed.

Then backfill the wall with mainly pea gravel, covered with poly or fabric. Then put no more than about 6" or so of soil back on top. And then the grade around the house should be about 6" of drop in the first 6 ft.

After you get it straight you could lag a few 4x4s to the wall vertically to help keep the wall aligned. That would look best if you did it on the back side, but it would mean excavating more.

Hope there is some sort of floor drain down there at the bottom.

 

A huge funnel to collect water right in front of a basement door. Someone just had to have a door there and I don't see a drain in the pad at the base of the stairs. Nevermind where a drain would drain to...

I see only a couple possible dead men and the wall is constructed poorly. There is very little strength between each row of timbers so, even though there is a dead man you can see how the timbers above are moving outwards.

It also looks like someone caulked the joints between the timbers. A very big mistake. That traps water behind the wall, dramatically increasing the pressure trying to push the wall over.

Best would be to replace the walls with ones properly constructed. Of course this is the most expensive and destructive option but would offer the longest term solution.

You can do as XSleeper mentioned but that system relies on water drainage. You must provide a way for the water collected by the stone to drain away. Since you are below grade it will likely need a sump & pump. In addition you can also install additional steel dead men with vertical bracking on the inside of your stairway to support the whole stack of timbers. But, you have to weigh those expenses against the limited lifespan of a wood retaining wall.

You are digging way too far away from the wall. You need to dig a narrow trench immediately behind the wall. Your very broad, though very shallow, excavation will expose the dead men if you keep digging then your problems and expenses will really start to build up. Those dead men must remain undisturbed in virgin soil. The minute to dig them out they quit working.

 

Thanks, Guys. I appreciate the replies. really. Yes, there is a drain at the bottom and it flows to a sump pump. Yes, I know I am digging too far from the problem. The project also includes, after straightening the wall, regrading that area. It was getting pretty back flow-ish and the water didn't have anywhere to go.

I'm afraid the ideas you guys gave me exceed my expertise level. If anyone has additional ideas, I'm still looking.

Thank you.

 

It probably wouldn't be DIY but there are steel deadmen that can be installed as a retrofit. They bore a hole through the wall. Then drive a folding dead man and rod through the hole. They add on extensions if needed. Then once they are driven in far enough they hydraulically pull back expanding the end as it grabs the earth. They can apply many tons of force to do some minor straightening and provide firm support for the future. You'd have to look at the cost to determine if it is worthwhile based on the amount of life left in your wood walls. You might determine that it's better to start saving a bit of money each year to do a replacement in 5 or 10 years.

 

I did what ex XSleepet suggested and it worked like a charm. The wall went back into place and looked beautiful. There was even a little separation between two of the timbers which looks like it would let the water seep through. But, as soon as I disassembled the jack setup, it went right back to where it was. So I know I can make the wall straight. Any suggestions on how to keep it straight? I'm considering leaving the one and a half inch lean at the top and just repairing the grading and hoping it doesn't get too much worse. If you all don't mind, would you weigh in some? Thank you.

 

Like I said earlier, you would need to lag bolt a 4x4 on the wall vertically to keep them all aligned. You would have to do that while you have it spread apart. You could do that on the inside, but it would be much better if the 4x4 was on the outside. Maybe you could dig down with a post hole digger or tile spade as deep as you can, get all the dirt off the back side of the timbers and then drop the 4x4 down the back side. Predrill holes through your timbers on the inside so that when you drive your lag bolts, it will suck the 4x4 on the back side up tight.

You could also look into having the wall professionally stabilized using helical anchors.