AU_Prospector

Hello I have a home built in the year 2003. I purchased the home inn 2007. The foundation is concrete block with several individual piers throughout the crawlspace. The crawlspace varies between 3-4 feet high. The problem area is below lot grade by about 1-2 feet.

There are two piers in the general area of the dining room. When it rains a lot or it is generally wet for several weeks like it is now, water will collect around these two piers in my crawl space. I dont know the significance of this, so I mention it anyway.

The pier I am mostly concerned about lies beneath floor joists which are about 3 inches apart, close but not touching. Above these two joists is a wall that divides my kitchen and dining room. Above this wall is a second story area with another wall that divides two bedrooms. Above that in the attic is support framing that extends all the way to the roof rafters. I can show pictures, but I assume this means LOAD BEARING from the crawl to the roof.

Anyway hopefully you get the picture. There is a narrow crack in the middle of some drywall coming off a doorway between the kitchen and dining room. This is not a seam crack. Upstairs the bedroom door is slightly out of square, but operates. The upstairs windows are out of square and difficult to latch closed. All symptoms have gotten only slightly worse in the 4 years I have owned the home. The wall between the kitchen and dining room is sagging in the direction of the wall where a heavy hutch is located. It is off maybe 1/4 - 1/2 inch.

In the crawl space there is about 12 feet of joist between the pier and the outer foundation wall in the area of the sag. It is also possible, though it might be my imagination, the pier is sinking just a slight bit. The crawl floor is packed clay/chert which is very hard. If you know about chert, when it rains hard, water will seep into the ground and run along the top of chert, which is why I think it collects around these piers.

My idea is to use steel foundation screw jacks to slowly support these joists to get it back in line or closer to in line. If the joists float above the piers, then I need professional help, but if I manage to get lift and all looks good, then this would be my permanent fix. My father's home had the exact same problem and the jacks he uses work nicely. My questions are about the footings. I plan to just use 4x10x14 concrete blocks and then use 4x4 wood to make contact with the two joists. Sound good?

nealtw

If the house had a new house warrantee. It would be good for the structure for 10 years, evan if you didn't own it when it was new.
Your plan sounds reasonable but for the concrete blocks. Just build cribbing out of chunks of 6x6 timbers or what have you. the concrete will just break.

BridgeMan

And before you start lifting things up, why not try to keep the water outside instead of allowing it to get into the crawl space? Extend your downspout drains, make sure gutters are flowing and functional, slope the ground away from the stemwalls, don't water landscaping next to foundation, etc.

If you use cribbing as nealtw suggests, be prepared for a significant amount of "crush factor" during your jacking operation. We always allowed 1/8" per wood-to-wood joint, meaning you could see close to an inch of crush before the joists start to lift. And you'd be better off to permanently shim between the joists and whatever beam they're resting on at the piers, instead of leaving screw jacks in place. And speaking of the (sunken) piers, exactly how large are they? Undersized units could be settling just because they're too small (exerting too much soil pressure for the applied load). Maybe you could measure the floor joist depth, joist sag (if any), and beam size as well, as long as you're down there. The more info you provide, the more advice you'll receive.

AU_Prospector

Okay here we go, first let me say something about the lay of the land water wise.

All downspouts around my home are connected in a system with a main discharge to the street.
My back yard is about 75 feet deep and open ground bordering forest. I sit on high ground and my lot slopes away from the property, EXCEPT in my back yard where the slope is about 2-3% toward the home. In general, however, water runs to the lots on either side of me.

The ground is HARD. Packed clay with chert intermixed. In summer it bakes rock hard. It is a little softer now with moisture, but is still difficult to dig in. Any rain 1" or more results in standing water in the yard. Hard rains results in obvious water movement across the ground, but not necessarily toward the house. Water percolation is SLOW into the ground and there is seepage into lower areas adjacent to my lot for several days after a hard rain or wet spell, but again my lot is higher than surrounding lots. I picked this on purpose.

Now for some data:
My crawlspace is about 2500 sq feet give or take 100 feet. It is not a rectangle, it has various 90 degree lines depending on the footprint of the rooms above.
There are 14 piers in total. Each pier is 15.5 inches square and composed of stacked preformed concrete blocks.
The area around the piers are dug out packed chert/clay presumably where they poured concrete footings. The dirt was
not replaced. Two of them collect water; the outer foundation on the backside of the home is almost always dark with moisture unless prolonged drought.

The joists run parallel to the problem area, not perpendicular. I liken it to a folded crease on a piece of paper.
The crease (and wall above) is about 9 feet in total, but pronounced directly under the 6 foot china hutch.
There is NOT a pier directly under the sag. Closest one is about 2 feet away to the side and not centered on crease.
This also happens to be the pier that collects the most water sadly.

The slope of the crease is about 3/4 inch per 4 foot on the dining room side of the wall both in the living area and in the crawl.
The slope of the crease is about 1/2 inch per 4 foot on the kitchen side of the wall both in the living area and in the crawl.

Attached is a picture of the crack in the wall that is on the crease, dining room side. There are no cracks on the kitchen side.
The doors and windows that are out of square upstairs are not so much as to be seen in a picture so nothing there. I can take more pics if you need something specific. I just noticed my hardwood floor directly below this crack is also cracked. The flooring runs perpendicular to the crease and the floor crack is about 1/16 inch in the grain.

nealtw

The pier I am mostly concerned about lies beneath floor joists which are about 3 inches apart, close but not touching. Above these two joists is a wall that divides my kitchen and dining room. Above this wall is a second story area with another wall that divides two bedrooms. Above that in the attic is support framing that extends all the way to the roof rafters. I can show pictures, but I assume this means LOAD BEARING from the crawl to the roof.

So if I have it right after reading this again; the load from the roof down is landing on 2 floor joists that are 3 inches apart. If that is the case the two floor joists should have been a beam that would carry that load to the piers.
I think you could still place a beam below, jack it up and support it with posts down the the footing beside the peirs.

AU_Prospector

Oooph, maybe I have this 'load bearing' thing all wrong.

I will go under the house again tomorrow and get some pics underneath. The joists are made of 2x10 lumber and normal spacing is 16 inch on center. There are two of these spaced closer together under the wall with about a 3 inch gap.

The second story wall isnt exactly in line with the first story wall, I thought it was at first, but it is about 18 inches off. There is bracing in this area above in the attic to the roof joists.

nealtw

If the wall above is load baring you will find a header over the door where the crack is. It will be just above the door way or just below the double plates near the ceiling. Drive a few nails and see if you can find a header. It would need to be there if the uptairs floor joist are landing on the wall.