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sagging outside brick wall
6

sagging outside brick wall

sagging outside brick wall

(OP)
hello everyone,

I recently did an inspection of a old victorian home in Toronto. While doing the inspection i noticed that the outside brick wall has sagged around the archway windows and in some areas of the wall. Upon closer examination there were no lintels installed in the window arches and I think that contributed to some of the settlement you can see on the pics.
The brick settlement seems to extend above the lintel as well however as you can see from the brickline above the window.

The house is constructed with two rows of brick on the outside wall. I didn't see any settlement at the foundation level although the outside wall seems to have concrete parging.

The client wants to know what the best recommendation is to repair this issue and if there are any underlying structural problems. They are considering a re-work of the outside brick veneer but wanted to know if there are any foundation issues. Any opinion on what some of the causes of the brick settlement may be and what other clues I can look for ?

Thank you!






RE: sagging outside brick wall

RE: sagging outside brick wall

Looks like a arch formed in the brick over the lower window. When that gave a bit, that led to the issues seen. (Looks like it's been fixed before.)

I'd definitely fix it with some kind of curved plate/angle over the lower window (as a form for the re-work at least).

RE: sagging outside brick wall

Looks like the whole left hand wall has sunk/collapsed by almost 1 course, and has been subsequently patched up at all the places it cracked.

RE: sagging outside brick wall

RE: sagging outside brick wall

Hey. The wall now isn't moving. Leave as is.

RE: sagging outside brick wall

The upper brick is caving as shown by Tomfh, but the lower part is not (so foundation looked ok). Other suspicious areas of movement indicating wall softening.

RE: sagging outside brick wall

Quote (OP)

but the lower part is not

The whole left side (red side) looks to be lower than the right side (green side)?

How has the top moved but not the bottom? Where the movement been taken up?

RE: sagging outside brick wall

It looks like the wall on the right has loosened, and rotate hinged on the windows. The overall displacement is quite small and spread over almost entire height. A level check can reveal level of distortion.

RE: sagging outside brick wall

I think that the arch failure due to mortar deterioration. It's common under windows because water infiltration at the sill will eventually lead the mortar to turn to just sand that will fall out of the joint. In this case, the left side of the unfortunate arch below is under the window and for many decades received water dripping down through the masonry. The deterioration over time caused the left side to slip and the bricks to compress. There's typically wood piece over the window in the shape of the arch, which probably held up the masonry before the wood rotted away.

They could have done the whole repair when they sloppily replaced the brick under the window. Oh, so close!

I'd say that a localized repair would be appropriate: pulling out the bricks under the window and re-setting the arch. When the outer wythe is out, the inner wythe can also be repointed, but it's probably better to remove the plaster and do it from the inside, too.

If you're really doing it right, you'd re-point the whole wall at the same time.

RE: sagging outside brick wall

Quote (r13)

The overall displacement is quite small

What do you mean by small overall displacement?
The left side looks to be about 1 course lower than the right side?

In my opinion there has been a major shift in the majority of the wall, with the difference in height showing up as arch failures. One side of the arches are lower because that whole side of the building has dropped.

RE: sagging outside brick wall

Small means there is rotation of area bricks without damaging the border elements - ridge and foundation lines, also no presence of noticeable wide cracks. The rotation is result of accumulation of microscopic joint separations in an area due to unequal softening, caused by weathering, or moisture. Due to shooting from an angle, the photos can be deceiving too.

RE: sagging outside brick wall

I'm with Tomfh on this one. It's tough to see it all the way down because the crack goes down to the bay window and gets lost at the change in material.

Here's a shot at the sill of the second floor window. You can clearly see that the brick opened up by nearly an entire course, and it was filled with mortar:


We don't have a good shot on the right side of the bay window at the foundation, but we do have the left side. Notice the crack in the slab running out from under the bay window. The coloration of the basement wall is also curious. Looks like the mortar parge was recently repaired. Can't draw any definitive conclusions from these, but I think it points to the possibility of some movement in the soils and perhaps some differential settlement.

RE: sagging outside brick wall

I don't see overall settlement. The coursing aligns on both sides of the failed arch, from what I can ascertain from the photo where I pull imaginary strings at the bed joints:

I think the crack at the bay window is more likely a failed lintel (I'm guessing wood) over the masonry opening at the bay.



RE: sagging outside brick wall

Quote (Kip)

The coursing aligns

In my opinion the coursing aligns because Side A has settled by a full course relative to side B:

RE: sagging outside brick wall

It the outer wythe a veneer or are both wythes forming the wall? It would appear from the header coursing that they are attached.

Do you have any locations that should be the same on either side of the house? A coursing line and run it around the perimeter. You could do this with a typical header course (bricks turned 90 degrees). The wall does not appear to be well constructed with the difference in coursing thickness and the header courses each 10 course... normally it's about 7 courses max and often 5 courses. Checking the coursing line around the building will give an idea of what has settled. It looks like Tomfh is correct and that the left side of the building has settled.

Has the arch been constructed as non-symmetrical, or has the building settled? The one repair seems to have one deeper course extending to two less deep courses. Are there other arches that have a similar feature? If not, why was this one constructed in this fashion. Relatively flat arches are normally no problem with masonry as long as you have sufficient wall abutment on each side.

Earlier repair has been poorly done using a concrete cement type mortar and this has caused failure of adjacent masonry wall.

The masonry appears to be in pretty rough shape and the fireskin on some of the units has 'gone'. Was the wall cleaned with an abrasive at some time in the past? I've loaded an earlier paper on historic brickwork to SRE's website; you might want to look at it.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

RE: sagging outside brick wall

I think it is optical illusion/distortion. Especially in the location marked "dogleg" through repair. The arch is very odd though, which contributes to the effect.

RE: sagging outside brick wall

Quote (r13)

I think it is optical illusion/distortion.

The wall is one course lower on side A. The repaired brickwork weaves across one course to make up the difference:




RE: sagging outside brick wall

The offset is limited in the repaired area. Some old damage (brick tilting) on the lower right remains.

RE: sagging outside brick wall

Tomfh is definitely correct about this,
It is highlighted in the picture below:





The differential settlement happens at the bay window so it isn't readily apparent in the foundation as the foundation isn't visible at this point.

RE: sagging outside brick wall

Did the slip coincide with what appears to be building a basement set of steps and a door?

That new piece of concrete wall looks mightily suspicious to me.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: sagging outside brick wall

FWIW, I'm on board with Tomfh's theory as well.

RE: sagging outside brick wall

I don't follow the green line. One is at the bottom of the window sill, the other one is on top.

RE: sagging outside brick wall

r13, exactly.
That green line is highlighting a course of bricks that is made up of smaller bricks. The green lines should be in line with each other and they are not.
This is also apparent with another similar course of smaller bricks at the bottom of the picture, the bottom yellow reference line has the small brick course below it on the left side of the window and above it on the right hand side of the window.

RE: sagging outside brick wall

The 20 courses arrows count 20 courses.

But they are not the same 20 courses...

The lines need to break either side of the windows and step up on course on the RHS to match the original lines of bricks.

also look at the horrible reducing "wedge" of bricks in the middle of the repaired section

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: sagging outside brick wall

(OP)
Thanks everyone for such great insights! Especially pointing out things I didn't notice initially in the pictures!

The client wants to resolve this issue. They are willing to do a rework of the entire sidewall bricks from foundation up to align the brick line. My concerns is that I'm not sure what kind of opinion I can provide on the cause of this settlement based on this limited information available ? I'm very reluctant to do so although the client will want to understand what is happening here! What additional information would be helpful to collect to understand any underlying issues without doing extensive intrusive work ? What recommendations can be provided to the client ?
If there is differential settlement of the foundation, perhaps it has stabilized over time. The house is over 100 years old in an old area in Toronto.

Thanks again everyone for all your great help! Truly appreciated!

RE: sagging outside brick wall

If they're going to go to that much trouble, get a geotechnical engineer involved. I don't think the settlement has stopped. Look at this picture. The crack next to the window has opened even more than the full course of mortar that's been shoved in there.

RE: sagging outside brick wall

Quote (LI)

The 20 courses arrows count 20 courses. But they are not the same 20 courses...

The lines does not lie, they all match brick joints on both side. The mess up is at the repaired area, somehow some of the old mess is still left in there without straighten.

RE: sagging outside brick wall

r13 - I have to disagree. Look at the bricks in the courses. As you know, in multiwythe brick walls, ever so many courses the bricks are turned 90 degrees to create a header course. Those header courses typically align all the way around the building. See the green line:

RE: sagging outside brick wall

Again, a straight/leveled line can be drawn connecting brick joint on the two ends. The mess in the middle has distort the view badly.

RE: sagging outside brick wall

Quote (R13)

The lines does not lie, they all match brick joints on both side.

Yes the courses line up on both sides. This is because one side has settled by 1 whole course, meaning the two sides are back in alignment.

RE: sagging outside brick wall

Tomfh,

Sorry, I couldn't get your point. Give me some time, may wake up later :)

To Lobus,

IMO, the bricks to the right side of the second floor window are softening due to moisture and weathering. At one time, the water infiltration was so severe that caused damage above the window (the repaired area). As pointed out before, the brick wall seems have rotated slightly, thus the large crack with mortar filling at the window flashing. You shall also pay attention to the deteriorate bricks just above the foundation. The water may have gotten there too.

RE: sagging outside brick wall

r13, I'm beginning to wonder if you really don't see it or if you are just messing with us all at this point.

RE: sagging outside brick wall

R13, just follow the courses that have the half bricks, which show up in your last picture below your bottommost yellow line on the left of the window; but, on the other (right) side of the window, the half-brick course is above the bottommost yellow line. It would be extremely unusual for that bit of decoration to be off by one course in the design; it's possible but unlikely.

TTFN (ta ta for now)
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RE: sagging outside brick wall

First thing I would check is if that original foundation has been replaced with a concrete footing and basement wall or if it's just a parge coat making the original (clearly failing) foundation look pretty.

RE: sagging outside brick wall

dauwerda,

Judge yourself.

RE: sagging outside brick wall

All of the lines I drew follow a course bedding. Your black line (that starts at my bottom blue line on the left) does not, it leaves a bed, goes through bricks and enters a new bed in order to stay straight. This is because the entire left side is one course lower than the entire right side.

RE: sagging outside brick wall

Quote (OP)

If there is differential settlement of the foundation, perhaps it has stabilized over time. The house is over 100 years old in an old area in Toronto.
I'd expect the settlement to be fairly over unless some changes in the nearby soil occurred. Has anyone near the house done some work that perhaps required drainage or that may have re-routed the flow of water?
That may be the cause, since you're asking about that.

RE: sagging outside brick wall

Check the header coursing...



Just about the same slope as the window arch...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

RE: sagging outside brick wall

This is how the repair was done.

RE: sagging outside brick wall

r13,

The header courses do not align. The left side is 1 course lower than the right side:



The left side has to have settled, breaking the brickwork between the windows in the process.

RE: sagging outside brick wall

Tomfh,

You could be right. Which will be a nice finding to put on the report. The OP shall check level of the wall.

RE: sagging outside brick wall

Tomfh is definitely right about the fact that the left side of the wall has settled 1 course relative to the right side of the wall. It is obvious, because you can see that the header courses on the left and right do not align, and are instead off by 1 course. For those having difficulty following this, I think some may not be familiar with multi-wythe brick construction and what a header course is. The courses of "half" bricks that you see every 10th course are the header courses. They are not half bricks, but regular bricks turned 90 degrees so that the long dimension is perpendicular to the plane of the wall. Thus, the bricks in the header courses are embedded in both wythes of the brick wall and therefore tie the two wythes of the brick wall together. Look at the header course that crosses the repaired area (the middle green line on Tomfh's picture above). There is a clear step/dogleg in the header course that had to accounted for in the repair by using a wedge shaped repair to transition one course into two courses.

The question is why/how has the left side of the wall settled relative to the right? I agree with LittleInch that the basement stairwell/entry area seems a bit suspect. I would suggest that the OP investigate that area a bit more for any previous repairs/modifications.

RE: sagging outside brick wall

I agree it's important to understand the history, and what action (if any) was taken to underpin or otherwise stabilise the wall. If someone did remedial footing works there should be direct evidence of it. The owners can surely provide some information too, even if only the date they acquired the property.

I'd also recommend using a laser level around the whole perimeter to get a clearer understanding of the extent of the settlement. They are so useful for seeing how a building has moved.

RE: sagging outside brick wall

hardbutmild - I'm not so sure it's stopped. Check out the sill of the second floor window, just above the bay window roof. On the right side, the joints are opening even more despite almost a full course of mortar being packed in there. It may well be the result of a recent change in the area. I think a geotechnical engineer would be a worthy investment here.

RE: sagging outside brick wall

I'm convinced. The coincidental alignment of the bed joint tricked my eyes, but there's too much contrary evidence:
1) header course sift;
2) foundation work done where you would expect the shift;
3) facade work done where you would expect the gargantuan crack to have been;
4) the bed joint shifts up at the gable above the top window;
5) there are certainly other issues/evidence inside this building where they fudged sloping floors, skewed windows, etc.;
6) in the photo with the broom and rake, it looks like the neighboring building may be a candidate for a similar thread.

RE: sagging outside brick wall

Quote (pham)

It may well be the result of a recent change in the area. I think a geotechnical engineer would be a worthy investment here.
I'd expect this to be the case. Maybe I didn't explain well. I meant to say that if the settlement is still active after a 100 years, it's almost certainly because of some recent change in the soil near a structure.

RE: sagging outside brick wall

(OP)
I'm considering making recommendations to the client to retain a Geotechnical Engineer to investigate what underlying foundation issues may have contributed to this differential settlement. The owner's just purchased this home and have no knowledge of what kind of repair work has been completed in the past. The foundation parging does look recent but doesn't seem to show any issues ?
There also doesn't appear any evidence of any previous underpinning or remedial works to the foundation.

There are some great forensics here! I've attached a few more pics if it helps in any way. Thank you all for taking the time to analyze this in detail!





RE: sagging outside brick wall

Quote (lubos1984)

The foundation parging does look recent but doesn't seem to show any issues ?

Exactly. There's no telling what that parge coat is covering up.

RE: sagging outside brick wall

Thanks for gte447f's explanation on the multi-wythe wall construction. It is odd to lay the header in offset layers, but I doubt it is due to settlement. Are you guys suggesting the settlement has occurred as shown in the sketch below? Where is the vertical shear plane though?

RE: sagging outside brick wall

Not sure about real estate laws in Canada, but I feel like this condition should have been disclosed by the seller or at least flagged by an inspector. The buyer should have some kind of legal recourse.

RE: sagging outside brick wall

At the bay window. There's no picture at the foundation on the right side (based on the new pictures I'd say the back side) of the bay window. More than likely there won't be a visible break - there's probably a header over the bay window. I'm curious - any slope in the floor inside?

RE: sagging outside brick wall

@r13
I don't think that the vertical shear plane would even develop, it's easier for masonry to have some sort of staggered cracking pattern, rather than a straight one. If the part on the right is stiffer it would cause diagonal cracking (at about 45° clockwise from the horizontal) as the left part was lowering because the bricks are interlaced.
Also, some masonry structures can deform with less cracking, an extreme example would be the ancient byzantine masonry that's famous for having very thick bed joints to allow for significant displacement.

RE: sagging outside brick wall

There were already a few posts depicting the shear plane, but here is another:



Also note the angle of the sill in the above image.

RE: sagging outside brick wall

@r13, Look at Tomfh's first annotated picture post (5th post in thread on 2 Dec 20 23:04). The "vertical" shear plane is sketched in red. Most of the shear plane occurs through the 3 window openings at the 1st, 2nd and 3rd story levels. The only real resistance through the masonry is between the top of the 2nd story window and bottom of 3rd story window, and between the top of the 3rd story window and the roof line, and it just so happens that those two areas are where the brickwork has been previously repaired.

RE: sagging outside brick wall

Quote (HBM)

I don't think that the vertical shear plane would even develop, it's easier for masonry to have some sort of staggered cracking pattern, rather than a straight one.

I agree that there may not have visible vertical crack, for a smaller amount of settlement over considerable distance. However, the vertical offset is nether small, nor far apart (over a window). There should be at least a vertical strip of bricks exhibit distortion. Other than the damaged and badly repaired area, I don't see such indication.

RE: sagging outside brick wall

dauwerda beat me to it. Excellent depiction, dauwerda.

RE: sagging outside brick wall

dauwerda,

It is culpable, but I reserve my doubt.

RE: sagging outside brick wall

r13 - the bricks did crack apart and shift. That's why somebody ripped it out and put that abomination of "masonry repair" in between the second and third floor windows.

RE: sagging outside brick wall

r13 - if you have doubts, where are they coming from? What is your theory that doesn't involve foundation movement?

RE: sagging outside brick wall

r13, what other explanation is there for what is happening in the picture below?

RE: sagging outside brick wall

The black straight lines trace the header layers. The yellow lines simply connect those lines. The red lines are suspected cracks.

RE: sagging outside brick wall

Right...but where is it going? At some point the movement has to be reconciled.

RE: sagging outside brick wall

You have stated the key phase that draw my suspicion - it is a built-in defect originally to correct some type of mistake, that may not be settlement though. If the arch has settled after construction, there should be noticeable cracks and repair works around the interface, especially to the left end of the arch, as well as to its right.

RE: sagging outside brick wall

pham has raised a good question. Can brick alone to absorb the not so small differential settlement?

RE: sagging outside brick wall

What are these, then?

RE: sagging outside brick wall

Quote (r13)

Can brick alone to absorb the not so small differential settlement?

Absolutely not. If it could, we wouldn't see the giant hole in the wall that was repaired, or the open joints 4" tall packed with repair mortar.

RE: sagging outside brick wall

pham,

Note the offsets happened on wall below the window too. The upper arch has an obvious crack repair done, the lower arch is not so obvious. Actually we are all guessing here, why not let field survey tell the fact.

RE: sagging outside brick wall

At the spring, no, but between the bricks you can see variations in the joint width from joint to joint. So can that arrangement take up the rotational displacement - to a point. If we had hi-res close ups, I'm sure there'd be some obvious gaps and likely some missing mortar in the arch joints. You can also see rather plainly the slope in the arch. Look at the window further to the left. It's nice and even - just as you'd expect in what amounts to a small mansion where I live. I'd be willing to bet that it is not a construction defect - who would spend that kind of money, look at the arch and say, "meh - no big deal." Nobody.

RE: sagging outside brick wall

The lower arch (and some brickwork above it) has rotated as a whole unit. That’s why there’s no step through the arch.

RE: sagging outside brick wall

Tomfh,

You are correct on the rotation of the entire lower window arch, the thing bothers me is the lack of huge cracks, or apparent repair, at the left side/corner to accommodate the rotation.


RE: sagging outside brick wall

There’s white mortar around the left end of the arch. Presumably it rotated there?

RE: sagging outside brick wall

What does the inside look like? Cracked walls? Settled floor?

RE: sagging outside brick wall

Tomfh,

Could be.

RE: sagging outside brick wall

Great discussion here.

R13, while I dont agree with your hypothesis it is well argued. Which i feel one would have difficulty trying to challenge this in a formal (with no further info than the images).

I believe we don't see the large cracks as noted because the majority of the movement has occurred at the window. The movements is hidden in minor cracking in the mortar joints as indicated by others.

RE: sagging outside brick wall

I hope you have convinced me, so I can do other things more interesting :)





RE: sagging outside brick wall

(Pic 1) Too neat the uniform drop of wall on left of the window, or rise on the right. Note the location of the bay window.

(Pic 2 & 3) The wall base elevation drop before and after the bay window might have contributed to the mess up of header row alignment.


RE: sagging outside brick wall

Suggestions on to do:

1) Perform level and plumb survey on the building to identify tilting, if any.
2) Inspect the wall-roof joints to identify hidden cracks, if any.
3) Inspect building interior to identify damages, if any.

If none of the above inspections yields meaningful result, I would suggest to perform cosmetic repairs on the wall (replace the deteriorated bricks), and repointing to seal the cracks, softened joints. that allow water to seep through. IMO, it's not yet the time to spent a fortune on an ugly but functioning wall, at least for another while. I'll leave the repair of the arch to later time, on major rework, or complete wall replacement.

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