Sinking floor and wall

[jay156]

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

 

[jay156]

Here is a photo of the door from the outside. You can see the diagonal cracks above showing the left side of the door is moving down and the right side is not. (Or that's what I think anyway).

 

[jay156]

Here is another picture of the door with the pavement showing too. It looks as though it has settled as well.

 

[jay156]

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.

 

[jay156]

Here is a plan view, to clarify.

 

[JAE]

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.

 

[BAretired]

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

 

[ishvaaag]

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.

 

[jay156]

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.

 

[msquared48]

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

 

[jay156]

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.

 

[BAretired]

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

 

[cvg]

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?

 

[BAretired]

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

BA

 

[msquared48]

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

 

[msquared48]

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

 

[BAretired]

Only 50,000?

BA

 

[msquared48]

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

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

 

[BAretired]

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

BA

 

[msquared48]

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