Strange House-sinking problem

[Molo]

I am sitting here at my computer in the den. I am in a ranch home built with a small crawl space under it. The change to the home is that there is now a 1" gap between the base molding and the floor. Also, I can slid a pencil under a wall and not even hit the bottom plate stud because it is also up in the air above the floor.
Does anyone have any idea as to why this is happening?

TIA,
Molo

 

[TedL]

I can think of two, but there's probably a lot more possibilities:

Rotting joist(s) letting the floor sink in spots.
Deteriorating foundation letting the floor sink in spots.

 

[Sponsor]

 

[Jadnashua]

INadequate footers? Got a sinkhole under the house? Any mines in the area (maybe over a 100-years old)? Take a close look at the foundation - check for cracks, bows, tilting. This could get serious; hope it isn't.

 

[Molo]

We're in New york state in a valley (no serious land movement that I know of). I'm guessing the joists are sinking/rotting. It is strange the way the floor has actually pulled away and left the base molding and the footer plate for the interior walls in the air.

Molo

 

[TedL]

We're in New york state in a valley (no serious land movement that I know of). I'm guessing the joists are sinking/rotting. It is strange the way the floor has actually pulled away and left the base molding and the footer plate for the interior walls in the air.

Molo

Over what period of time has this gap developed?
How old is the house?
Is your foundation poured concrete/block, or stacked stone.

You do want a pro (e.g., structural engineer) to look at it.

 

[Molo]

It seems as if this has happened over 2 years. It is a block foundation with a 2 foot crawl space below the joists. The home is 50 years old.


Molo

 

[TedL]

Well, the "new house" settling should have been over long ago, and the mild winter most of NY has had should not have challenged the foundation.

How wide a span shows the gap? Inside or outside wall? Bearing or partition?

 

[hj]

gap

The gap is not strange at all. The wall has plates, studs, and sheetrock keeping it "square", but the floor is sagging in an arc. The wall cannot distort to match it, unless the roof were also caving in to push it down, so the gap develops. At least when you drop anything on the floor it should all roll to the middle where it can be easily found.

 

[Molo]

The walls where it is most noticeable are the walls in the middle of the house (load-bearing and non-load-bearing). I wonder how bad this will get. It would be a job to get under there and do work.

Molo

 

[Jadnashua]

I wonder if the joists are overspanned or overloaded? Do you have any exceptionally heavy things? Done any signficant tile jobs with deep mud beds? Lots of bookcases? Something not "normal"?

Blocking between joists helps keep them from twisting too much; you might have some pretzels down there. A joist or two could have been chopped up for plumbing or HVAC and split.

Definately something to check and fix.

 

[Molo]

No heavy things, no recent work. The only idea that I have at this point is the tremendously wet summer and autumn that we had this year. Plus improper span. This might require some steel and some jacks in the crqwl space huh

Molo