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Sinking floor and wall

Sinking floor and wall

Sinking floor and wall

(OP)
Hi, I looked at this masonry garage yesterday and the back door was way out of square. Looking at the garage floor, one side has settled approximately 3/4". The pavement outside the door is the same. Looking at the masonry above the door, I saw two parallel diagonal cracks, which looked to indicate that the one side of the door has settled while the other one hasn't.

My first thought was that the wall to the right of the door was settling, but the house is about 70 years old, and when I went to the basement, I did see a little diagonal cracking at one end of the wall, indicating some settlement, but it didn't look like enough to cause such a big movement upstairs.

The lady who owns the home told me she had the garage floor replaced about 5 years ago, and a drain pipe put in below it, and that's when the problem started. Could the settlement of the floor cause the wall to go like that, even though it's not really tied into the wall? Could there be another cause? I suspected that the wall next to the floor was settling and causing the floor movement, but it doesn't look like it, and there was no problem until the floor was replaced.

I attached a picture of the door. You can see that the floor has settled on the right and caused a crack between the doorjambs. More pictures coming.

Thanks

RE: Sinking floor and wall

(OP)
Finally, here is the basement wall. The glass block window here is the same one as in the picture in the post directly above this. So the wall with the door is perpendicular to this one, off to the left. You can see there's some settlement, as evidenced by the diagonal crack below the window, but not as much as I would have expected to cause such a big movement in the door above.

Apparently the lady hired a mason who thinks it's because of the floor settling that the door is going out of square, and wants to pump mortar under the floor to support it, but I don't see how that could be causing the problem.

RE: Sinking floor and wall

jay156,

It would appear that the foundation settled downward to the right of the door (as you look from outside in).

The two diagonal cracks appear to represent the wall to the right rotating downward, the upper right hand corner of the door is the fulcrum, and this is lifting the header over the door, causing the diagonal cracking at the left upper corner of the door.

The fact that there is little distress in the basement to the left of the door doesn't negate the possibility of this foundation settlement - it appears that there is little distress in the intersection of the two walls (the re-entrant corner looks uncracked) so the movement, and damage, are confined to the wall with the door in it.

 

RE: Sinking floor and wall

Let's suppose the plan view is drawn with north upward.  Then the wall intersection just west of the door appears to have settled relative to the wall east of the door.  The resulting diagonal cracks have been patched before.

What was the purpose of the "drain pipe" under the garage slab?  Where is it located?  Is it possible the pipe is plugged up and wetting the soil under the foundation just west of the door?  This could cause settlement of interior and exterior slabs and both walls.  In that case, pumping grout under the slab will do nothing for the foundation under the walls.

BA

RE: Sinking floor and wall

On the images I agree with JAE. You also say the pipe was put under the garage that I am assuming is also on the shown lower part of the building... so we would be having the settlement where the potential water leakage of the pipe suspicious to the lady is.

RE: Sinking floor and wall

(OP)
The pipe was put in to be a garage floor drain, but then the building department said they couldn't tie into the storm, so rather than go to the sanitary, they just abandoned it. I don't believe it's tied into anything (well I hope not), but I will ask the owner if it's somehow tied into the storm with no floor drain at the upstream end.

I think also that the west intersection, as shown on the plan, has settled, but I'm not sure what caused it to suddenly do so after 70 years of being okay, and I'm surprised to not see more damage to the wall in the basement. The other end of the wall (To the left as you look at the basement picture) is covered by paneling. I suspect that if that were opened we might find a bigger diagonal crack over there.

RE: Sinking floor and wall

I can see the very strong possibility of settlement to the right of the door and understand what JAE says regarding the fulcrum issue, but have never seen this particular crack pattern before.  

Seems to me though for this to be the case that the door could be the stiff vertical element causing the uplift on the left side (it appears to be metal?), and consequently binding the door.  Can the door be opened?  I just don't sense the stiffness in the door header to do this.   

Mike McCann
MMC Engineering
Motto:  KISS
Motivation:  Don't ask

RE: Sinking floor and wall

(OP)
The door can be opened only because they keep planing the door header.

I just find it strange that the wall hasn't settled for 70 years, but after only putting in a new floor, it is settling.

RE: Sinking floor and wall

There seem to be two schools of thought in this thread.  One is that the wall to the west of the door settled.  The other is that the wall to the east of the door settled.  

I'm from the earlier school.

BA

RE: Sinking floor and wall

how about water got into the drain, leaked into the subgrade and saturated the expansive soil causing the floor/wall to rise not settle? Assume the floor drain is somewhere to the northeast of this door. Additional dead load at the west side wall intersection prevents this area from moving as much (upward) as the lightly loaded garage slab east of the door. this would wrack the doorframe as shown in the photo. Is there any corresponding cracking on the north side of the garage at the connection to the house?

RE: Sinking floor and wall

Heaving is certainly a possibility if the soil is a clay.

BA

RE: Sinking floor and wall

In looking more closely, as BA suggested, heaving, on the right side of the door, is a strong possibility too.  Note that the exterior slab terminates at the right side of the door, and water drains to that side. I also note that the same slab is showing distress in the upper left corner, like a vertical settling.  

I am wondering if an abnormal amount of water is getting to the foundation at the right side of the door, causing a vertical expansion, either due to frost heave, or a clay foundation layer expansion.   

I would really like to see what is going on behind the garbage can as I see what appear to be a few loose bricks on the ground.

What is the wall top plate doing vertically in the interior of the garage where the roof framing bears?  How does the elevation of the top plate at the intersection of the house compare to the elevation at the door frame, and further to the right at the corner of the garage?    

Mike McCann
MMC Engineering
Motto:  KISS
Motivation:  Don't ask

RE: Sinking floor and wall

By the way, since BA is retired now, is he good for another 50,000 miles?  

Mike McCann
MMC Engineering
Motto:  KISS
Motivation:  Don't ask

RE: Sinking floor and wall

Only 50,000?

BA

RE: Sinking floor and wall

That's the current line in Vegas BA...

Mike McCann
MMC Engineering
Motto:  KISS
Motivation:  Don't ask

RE: Sinking floor and wall

Wouldn't know, m248...I'm just a country boy.

BA

RE: Sinking floor and wall

Don't tell me!!!!   

You're first name is really John, and you're from Denver!

Mike McCann
MMC Engineering
Motto:  KISS
Motivation:  Don't ask

RE: Sinking floor and wall

Can't say that, Mike but sunshine on my shoulders makes me happy...sunshine almost always makes me high.

BA

RE: Sinking floor and wall

(OP)
I don't think this is due to heaving, only for the reason that at the front of the garage (north on my plan), the top of the garage slab and the top of the driveway are flush on the east side of the garage. On the west, near the wall we think is settling, the garage floor slopes down leaving the driveway sticking up about 3/4". (See attached sketch). So I'm pretty sure it's settling (though I suppose the driveway could have heaved exactly the same amount at the east end, but it's not cracked). The only unknown is whether it's just the floor settling, or the entire foundation wall.

It doesn't seem likely that just the floor settling would cause the door to be that out of square. I think it pretty much has to be the foundation, though I don't know what could have caused it to suddenly start settling, unless that pipe they put in, (probably 6 feet higher than the footer), somehow caused the earth 6 feet below it to weaken. That doesn't seem likely either, so I'm kinda lost.

Any ideas?

RE: Sinking floor and wall

At first glance, I agreed with JAE's premise, but then started looking further. I still think JAE is correct; however, I think the door issue has a different source.  Also, the gutter slope does not follow the brick slope, so that's a bit of an optical influence supporting the settlement on the far right looking from the exterior.

If you look at the inside picture of the door, you see a masonry header that has been installed since the original masonry was done.  This header is much newer.

The right end of the header corresponds to the exterior cracking.  There is also sealant installed in the joint here that seems to match the sealant from the exterior.

The door is binding on the latch side, just below the header.  If you look at the crack on the outside, it would appear that the brick over the door on the crack side is lifting upward as JAE described the fulcrum effect.  That's not consistent with what's happening on the inside.  If the fulcrum were in action, the right side of the door, looking from the inside, would have a gap, not a binding condition.

Looking at the slab crack, it appears to be relatively minor and likely a restraint condition, not settlement.

I suspect that the installed head is not properly supported and bears on the door frame.  Notice the other side of the header has a half-block support, while on the cracked side, it appears to bear on brick and the door frame.

 

RE: Sinking floor and wall

I don't know if I'm correct or not - really would need to study the horizontal elevations of the foundation walls, brick course lines, etc. to know what went up and what went down.

 

RE: Sinking floor and wall

(OP)
Thanks Ron, I think though that more than just the header is moving, because while there is a binding condition at the top of the door, there's also a gap through which you can see daylight at the bottom of the door on the latch side. It appears that entire end of the wall is moving.

RE: Sinking floor and wall

Jay:

You really need to see what the top plate is doing elevation-wise.  Can you make a plan of the garage and take a few shots on the top plate elevation and post the results?

Mike McCann
MMC Engineering
Motto:  KISS
Motivation:  Don't ask

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