Forgive me if I've placed this in the wrong forum. This seems to be the go-to foundation forum, though in reality this is more of a framing problem.

We're undergoing a massive foundation reconstruction for a 1920's two-story + basement lath, plaster & stucco monster.

Prior to the work, the house was out of level by as much as 8". We lifted it on steel beams, and yesterday set it down on its new, level foundation.

The problem is that one corner is sitting about four inches off of the foundation plates. Maybe 20' in each direction (from that corner) are hanging in the air before touching down.

It seems that after decades of sagging in the middle, this corner has formed a "memory" and is quite happy where it is.

The contractor is thinking of using all-thread to pull it down, but this would be pulling on the joists and the subfloor, but not the walls above. I'm worried that this may cause more problems, by pulling the floor away from the first-floor walls.

Another option is to let it be, and shim the foundation up to meet the house in this location (leaving the floor out of level).

Or we can search for other creative solutions, but contractor time is money and that's something we're short on.

Any sure-fire solutions we should shoot for? Barrels full of water? Circus elephants? Spent uranium?

 

Time. Let it adjust for a while (make sure that your contract lays out the time frame, and what will be done when that time expires).

 

Tscarborough is correct about letting it adjust but I would give it a little help. Set up a "come along" vertically on that corner. Put a little tension on it and add a little more tension as time passes. By time you finish the other work, it should be close to level.

 

Another thought: Are you certain that the foundation was ever level to begin with? I admit it's very unlikely, but is it possible that the home was built to fit a bad foundation at the outset? If so, maybe the framing that is now sticking up was simply cut shorter to accommodate a corner of the foundation that was taller.

 

As Pecos said, do some measuring and see if it is just memory or design. If all of the walls are the same height, it is memory. If the walls in that corner are shorter, it is by design. Assuming it's memory, then move it along with some pressure, "the come along". Since it is still in the "move" condition, consider a compactor. One that will adjust form low vibration up and run it from room to room. Letting it sit is essentially time and normal activity wiggling everything into place. Accelerate the wiggling and shorten the time.

OR, if you choose to pull it down, run a cable or two up through the floor to a new cross beam in the attic, so you will be pulling down on the entire wall assembly. That will help hold things together. Of course once you get it down that way, you still have to consider what will happen once you release the tension on the cable. You may have to leave a cable in place inside a wall.

Shake it down,
Bud

 

Thanks for the suggestions.

In answer to Pecos' question, it's not clear if the foundation was level to begin with, but it is evident that at some point a previous owner attempted to address an out-of-level condition by installing a false floor in the kitchen. So it's difficult to get an accurate measurement of floor to ceiling heights.

It's down to about 2" now. The contractor installed all-thread at three locations and is attempting to coax it down. However, as I feared, this appears to be putting unnecessary stress on the joists he's pulling on.

 

How is the stress manifesting itself? Are you seeing cracks in the walls and ceilings?

 

Contact whoever specializes in moving houses in your area, and get them to come out, take a look, and make suggestions.

I'd love to see some before and after pictures of the corner by the way.

 

Pictures!

Here's the house we're starting with.

Backstory: 1920's construction, built on top of a landslide in the middle of earthquake country. The house is as much as 8" out of level, with a sagging living room floor due to a missing vertical support down below.

Project scope: construct a liveable space on the ground floor for the parents to reside, saving them a 20' climb to the bedrooms. Beef up the foundation to current seismic standards. Level the house. My wife and I will move in upstairs. The middle floor will be common access -- kitchen, dining room & living room.

This is a few days after construction, and the wood stairs and front porch has been demolished.


The trench represents approximately how much farther we're digging down to get below the landslide, onto stable dirt. The new foundation slab will take 18" of this. The house itself will be lifted to accomodate demolition & construction, than lowered back to its existing height.


This is the access hole the contractor poked into the house to begin preparation for the dig-out and lifting.


Here is a good illustration of the existing floor height, and how much farther down we're digging.


A shot from the front, with the house lifted off of the old foundation.



The old foundation wasn't substantial, and was badly failing. I'm told the house was mostly off the foundation along the rear.


A challenge was the neighbor's house, which is very close. Our project is essentially digging an 11' cliff right up to the other house's foundation (also failing).


To shore up the neighbor's property, our contractor bored down and poured hold-back pillars. This was also done along the back side of the house.


Jumping ahead, this is just days prior to the pour of the main slab. The 18" slab is heavily reinforced with steel. A second big concrete pour will fill in the three crib pits and tie in some work at the front of the house that's not yet ready.

 

This next series focuses on the back wall, underneath the kitchen upstairs.

Prior to lifting the house, dirt sloped up to meet the ceiling at the back. The contractor dug this out using handheld power tools. This was done by hand to make way for the steel beam & crib needed to lift and support the house.


After lifting the house, the big guns came in and started mechanical excavation. This is the same wall, dug down about half way.


It was dug out in two phases. The dirt was stabilized with shotcrete and steel tied into the pillars. Notice the light colored stripe across the dirt. This is the separation layer between stable soil (below) and the landslide soil (above). We're now clearly below the landside, into "good" dirt.



The walls were reinforced with a double layer of steel before application of structural shotcrete. The concrete is 12" thick along the back, and 8" to 10" in other locations.


Here's the finished back wall, from the same perspective as the first photo. The shotcrete has been smoothed on the right, as this will be a utility room. On the left, it was left rough, and we will apply a nicer finish to it after completion.


The next four photos are of the back corner (the kitchen). This corner is the location that "stuck up," as I talked about in my original post in this thread.

Near the start of the project, after the demolition of the concrete patio.


Three pits were dug in the back yard to place cribs to support the steel beams. Concrete pads were poured inside the pits to address the issue of soft, wet dirt.


After lifting, this is the same corner of the house as viewed from the side. We had a lot of dry rot in this location.


The back wall was reframed to support the weight of the house upon lowering. We still have much work to do in this location, including replacement of the rotten window.

 

Because of the warped floor, we had a problem when setting the house down. The kitchen didn't touch down to the foundation, and worse yet, the middle of the house had a "belly" -- a low spot. So most of the weight of the house came down on this woefully inadequate temporary wall, framed of 2x4s. Upon noticing this, the contractor quickly re-lifted the house and reinforced the walls.


To address the problem of the kitchen hovering in the air, pull-downs were fashioned out of brackets and all-thread. We all want to be sure the house is done moving before we begin the work of building and repairing walls.


Here's a shot of the gap between house and foundation four days after it was set down.


Same shot yesterday, three weeks after touchdown. We've got a little ways to go, but it's quickly getting there.


The next five photos picture samples of the resultant damage from the leveling of a structure that's been crooked for over half a century.

This is an archway near the center of the house. It's not original work. We're seeing damage like this on three arches on the main floor.



This is the about the worst wall failure. The top of the door frame is now sloping down about 5° to 10° to the left.


This damage was helped along by water intrusion. I pulled it apart prior to taking the shot, but the whole exposed area bulged out like a bubble and cracked.


This is about the worst exterior stucco damage we could find. It's on the other side of the toilet in the photo above. There was also some minor, hairline cracking in other locations.


The roof completely failed. With the center of the house raising, and the one corner being pulled down, the roof couldn't handle the tension and simply into two pieces.

 

Nice little weekend project!

Great pics, thanks.

 

Thanks. This has been going full swing since September, and although we aren't even contemplating a move-in date, we know we're getting closer. We're still in the thick of the project, with one more huge concrete pour to go (probably another 80-90 yards).

Documenting the project has been a blast. Hundreds, if not thousands, of pictures are littering my hard drive. The best of them get emailed out to friends and family as semi-regular photo album updates, narrating the project.

On the day we lowered the house, I rigged up a camera on a nearby telephone pole and shot the following time lapse sequence. Not quite as dramatic as I had hoped it to be, plus a couple of technical glitches I should have anticipated, but still fun to watch.

Lowering the House... Twice! on Vimeo
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Lowering the House... Twice! from ɐǝsʇǝd uɐʇǝɐ on Vimeo.