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
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
RE: Sinking floor and wall
RE: Sinking floor and wall
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
RE: Sinking floor and wall
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
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
RE: Sinking floor and wall
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
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
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
I'm from the earlier school.
BA
RE: Sinking floor and wall
RE: Sinking floor and wall
BA
RE: Sinking floor and wall
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
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Sinking floor and wall
BA
RE: Sinking floor and wall
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Sinking floor and wall
BA
RE: Sinking floor and wall
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
BA
RE: Sinking floor and 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
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
RE: Sinking floor and wall
RE: Sinking floor and wall
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