Old Outbuilding Foundation

Should I dig out the dirt and put in drain tile and rock? Chisel out all of the mortar and re-tuck point?? Not sure if that is what it is called, and if so is it a tough job? Put a deadman in there and try to straighten the wall? Can that be done with a come along? The wall is about 25 feet long. Thanks

Most of the above problems could be addressed by digging out the dirt above the wall, repairing the wall, installing drain tile, and backfilling with crushed rock instead of the native soil. You are going to have to dig out the dirt no matter what -- you aren't going to be able to push the wall back into place against the pressure of whatever is pushing it in.

A normal block basement foundation is supported at its top by a floor diaphragm. It sounds like your building just transitions from block to wood, without any floor to help hold the walls back. This makes the job of the wall harder than usual, and I would consider using grout and rebar, together with a solid spread footer, in any such block wall. Alternatively, you might consider providing temporary support, demolishing at least the center third of the bowing wall, and putting in a reinforced concrete section. But it is hard to understand the whole situation without being there or at least having a photo.

Most people think "we don't build them like they used to", or that the old timers were real crafstmen and built stuff right, and to last. But if you take a look at a lot of older barns and outbuildings, you can see that many of the builders were ignorant of the basic principles of structural engineering and slapped stuff together without thinking about what was actually holding the building up. Sometimes that only reason the buildings have lasted this long is that they had access to old growth timbers you can't get today.

I think the "something" else going on is badly deteriorated mortar between the blocks. But maybe even more importantly I had a circle driveway put in and it probably channels the rainwater right against that wall. Also the eaves drop water right along that wall. You are correct that there isn't a floor structure at the block, it is about 4 feet higher than the block.

Someone said that because the bldg isn't heated drain tile won't have any affect. How would you "move" the walll back into place? I would be afraid that the whole thing would come down if you did it from the inside.

If pictures would help let me know. Thanks.

The wall can resist inward soil pressure due to the dead weight of the block and the building above, plus the sliding resistance of the footing at the base, plus any restraint offered by the floor or wall above, plus whatever shear strength is provided by the mortar.

Yes, your mortar has deteriorated. But if the wall had to restrain a significant load, even good mortar would not necessarily succeed. It would have far better to fill every other (or every third, or fourth) cavity in the block with grout and rebar. This makes a vastly stronger wall than ordinary unreinforced block. Or take Case450's advice, and replace it with reinforced concrete.

I think the real question here is why there is so much inward force on a 40 inch tall wall. As anyone with a backhoe can tell you, ordinary dry silt or clay soil can be cut at least this deep to a vertical slope which will not collapse (i.e. zero inward pressure). Moist, or sandy soil exerts a modest inward pressure, which gets worse as the wall gets taller. But at 40 inches, it is generally considered possible to hold back this much soil with an ungrouted block wall.

Soil which is completely saturated with water, or (worse) a wall which is trying to dam up ponding water, is quite another matter. You can't create "Bonneville dam", even a 40 inch scale model, using unreinforced block. The hydrostatic pressure is much too high. While you may not care if the inside of the structure gets wet due to leaks, nor will there be freeze/thaw effects due to frost (the "not heated" discussion). Nevertheless, it is important to provide drainage to get the water out of there, so the wall doesn't have to hold the water back (which it can't).

If there is a new driveway located within (say) 8 feet of the face of the block wall, I would say that is your culprit in the collapse. This is especially true if you did any filling of the area prior to installing the driveway. The water saturated and possibly uncompacted soil cannot fully support the weight of the vehicles, and is trying to "squish" out sideways against a wall which is ill-equipped to resist the large resulting force.

You have no real choice but to dig out the soil on the outside of the wall. You can't move the wall outward against the force of the soil no matter what you try.

On the inside, I suggest you provide temporary shoring and alternative support to the the floor, wall, and roof now being held by the block. Then rebuild the wall, using rebar and grout or following the concrete suggestions of Case450. Then provide for drainage on the outside face of the wall to prevent the ponding and saturation problems, and backfill with good draining and easily compacted rock. I'd try something like 1.5 inch drain rock, or even larger rock without fines, as that stuff is self-compacting and drains well.

The bldg is old so I don't want to put a lot of money in it because I would replace it with a pole shed. However, it is providing a place for hay right now and money is tight.

This is what I will do right now... Put up a gutter and provide a way for the water to stay away from the foundation. Come spring I will shore up that side of the bldg (most of the hay should be out), dig out along the wall, knock the blocks out (hopefully reuse) and rebuild. I can then tie it together with rebar and fill some of the cavities with cement. I will put a piece of drain tile down and back fill with rock. That should keep my cost down except my own labor. That may buy me a couple of years before the whole bldg comes down either on its own or with my help.