Thread: Bulge in stucco - structural issue?

We're considering making an offer on a home built in the 1950's in Northern California. We noticed a bulge in the stucco (pictures attached) on one of the walls. There's no crack on the bulge though. Does it look like an issue with the siding or a more serious structural issue?

FWIW the inspection report noted some "moderate cracks" in the foundation (picture) but didn't say how large they were. Would it be possible for foundation problems to cause the bulge?

Thank you

stucco_1.jpgstucco_2.jpgfoundation_crack.png

Similar Threads:

• Do I need a structural engineer?
• Bulge at rim joist...
• Structural pic
• Structural Concerns?
• Structural Settlement or Structural Failure?

Judging from the photos you have a concrete block wall foundation, and the bulge is in my opinion being caused by the downspout discharging against the foundation causing the parging to fail. Water will wick up the wall by capillary action.

The crack appears could be active or stable. Someone has marked the crack with chalk in order to ascertain movement. Further queries should be sought from the vendor in order to establish who marked the crack and how long ago was it marked. If it was marked several months or more the crack does not appear to have changed. The crack may have occurred sometime when the house was constructed.

I agree with Raymond, Jae. The puddle beneath the downspout indicates drainage running against the foundation, and down the joint between the pavement and home. All drainage should be directed well away from the structure. The joint itself should be properly caulked to help control moisture intrusion.

Stucco from the 1950's would typically be a traditional, multiple-coat assembly. The coarse, base coat (brown coat) is very porous. If it experiences frequent saturation, it can actually loose its adhesion to the top coat. Bulging is common enough before an exterior crack actually appears.

This can happen independently of any possible foundation issues.

I would encourage you to ask your inspector more questions about it.

Could be caused by several things, some minor and some not so minor - did you or your inspector tap on the bulge area to see if it sounded hollow behind the stucco?

A solid sound may indicate that the wall was offset over the edge of the foundation and they stuccoed down the wall and then back to the foundation.

A hollow sound indicates that further exploration needs to be done:
- Is it loose and unbonded parging?
- is it loose stucco from shrinkage of the wall?
- Is it loose stucco from termites or other infestation in the wall, which as allowed the weight of the structure to crush the studs shorter?
- Is it loose stucco from ... (I'll let the California guys fill in the rest)

Block wall or frame wall (I should have clarified this first).

Originally Posted by Jae Kim

We're considering making an offer on a home built in the 1950's in Northern California. We noticed a bulge in the stucco (pictures attached) on one of the walls. There's no crack on the bulge though. Does it look like an issue with the siding or a more serious structural issue?
FWIW the inspection report noted some "moderate cracks" in the foundation (picture) but didn't say how large they were. Would it be possible for foundation problems to cause the bulge?

stucco_1.jpgstucco_2.jpgfoundation_crack.png

Jae,

Northern California is pretty vague. I am located in No.Cal. and see a lot of that kind of thing. It is difficult to make an assessment from three photos and the limited description that you gave.

Can you give us a city?
Do you know if there are expansive soils in your area?
What kind of recommendation did your home inspector make?

Construction varies in different areas. In my area a bulge like that often results from Lumber shrinkage at the band joist (the floor joist at the perimeter of the floor framing).

It could also be deterioration of a band joist or sill plate. Seismic issues are another possibility. Theven are all issues that should be seen if the area is accessible.

That foundation cracks looks like a typical shrinkage crack. Based on the photo, it does not look like a concern.

My concern is with the stucco system not being properly terminated. Stucco is a drainable cladding. How is the system draining? I looks like it has been painted. If so and if the correct paint was used then drainage is not as much of a concern. If not you may want to have a stucco inspector perform moisture probing.

Originally Posted by stanley frost

My concern is with the stucco system not being properly terminated. Stucco is a drainable cladding. How is the system draining?

That was the reason for my question below:

Originally Posted by Jerry Peck

Block wall or frame wall (I should have clarified this first).

Seems that most are assuming that the stucco is on frame, but it might be stucco on masonry - there is a big difference between the applications, one big difference being that stucco on masonry is not a drainage system and does not require a foundation weep screed.

I don't recall that my question was answered, and that answer is critical to any postulation about any cause.

I am with Mark on this. Degraded rim joist.
No weep screed on Traditional 2 coat stucco. Sheathing, double layer of barrier, lath, one or 2 brown coats and stucco finish. Repaired many. Termination, a metal channel finish.

Originally Posted by ROBERT YOUNG

I am with Mark on this. Degraded rim joist.
No weep screed on Traditional 2 coat stucco. Sheathing, double layer of barrier, lath, one or 2 brown coats and stucco finish. Repaired many. Termination, a metal channel finish.

Yet another presumption that it is stucco on frame ... when we have not been told that is the construction type ... it "might" be masonry ... and "might not" be masonry ... but one should not make such presumptions ... ... especially as the very next post after a post pointing those presumptions based on no evidence.

I'm going out on another litigation site review on Wednesday ... presumptions are just not something that is acceptable to do

I think the stucco is likely on the foundation wall, since it looks like there is a crawlspace vent to the right. I would be surprised if any house in CA built in the 50's does not have some foundation cracks, since there have been dozens of earthquakes since it was built.

I agree though, that its just about impossible to determine much from the three photos.
Like Jerry said, I would want to know if the home inspector tapped on it, and had an opinion.

If there was masonry saturation at that point I would suspect efflorescence on the foundation and signs of past water migration and the plate to be rotted.

Originally Posted by Jack Feldmann

I think the stucco is likely on the foundation wall, since it looks like there is a crawlspace vent to the right. I would be surprised if any house in CA built in the 50's does not have some foundation cracks, since there have been dozens of earthquakes since it was built.

I agree though, that its just about impossible to determine much from the three photos.
Like Jerry said, I would want to know if the home inspector tapped on it, and had an opinion.

I concur Jack. We are looking at an image and can not determine the assembly.

a: Looks like a crawl space vent
b: If you zoom in on the bulge it is clearly not the same signature stucco finishing as the upper original stucco. There are wide quarter arches and at the bottom tight quarter arches from applying and smoothing concrete with a float. Stucco was likely broadcast with a hopper afterwards.
Look at the upper stucco as compared to the stucco at the bottom wall,what would be foundation.
Upper: stucco 1.JPG
Lower: stucco 2.JPG

Originally Posted by ROBERT YOUNG

I concur Jack. We are looking at an image and can not determine the assembly.

a: Looks like a crawl space vent
b: If you zoom in on the bulge it is clearly not the same signature stucco finishing as the upper original stucco. There are wide quarter arches and at the bottom tight quarter arches from applying and smoothing concrete with a float. Stucco was likely broadcast with a hopper afterwards.
Look at the upper stucco as compared to the stucco at the bottom wall,what would be foundation.

Those patterns are circular in appearance, which makes me think of a brush (parge coat) or a trowel, maybe even an notched trowel, on stucco with that finish (the aggregate tends to follow the circular path of the trowel).

That third photo answers the question of the construction type - wood frame and not masonry as the wood floor system is resting on a sill plate on that foundation wall ... and I confess that I did go back and look at that more closely - me bad.

Originally Posted by Jerry Peck

Those patterns are circular in appearance, which makes me think of a brush (parge coat) or a trowel, maybe even an notched trowel, on stucco with that finish (the aggregate tends to follow the circular path of the trowel).

Semi circular. Quarter circles. Likely notched and knocked down with a wood bull float.
That tells me it is non traditional.
Ever watched traditional plasters or stucco installers?
Up sweeps and large arches. Like the upper portion of the images.
I never used chicken wire, only diamond lath. I was not fast. Never did enough.
https://www.youtube.com/watch?v=i0hNsHCQFLU

Sorry for the edit. Look at the metal finish bead, stucco finish chanel, at the bottom.

Originally Posted by ROBERT YOUNG

I never used chicken wire, only diamond lath. I was not fast. Never did enough.
https://www.youtube.com/watch?v=i0hNsHCQFLU

Robert,

That link shows a stucco job which is likely to fail.

This guy puts it on better, still not quite right all the time, but more right most of the time: https://www.youtube.com/watch?v=zcvVlOMHeEo

The reason for the stucco job in your link will likely fail is that the metal lath (never ever use "chicken wire" - not allowed by code) is that the stucco is supposed to be fully embedded around the metal lath (the metal lath is supposed to be fully embedded within the stucco).

To do that, the stucco needs to be pushed up as it is being applied, then come back down over the stucco with the trowel to force the stucco into the metal lath and fully around the metal lath.

Additionally, the metal lath is to be installed with "cups up", when the stucco is applied properly with the downward pull of the trowel, the stucco is forced down and into the "cups", when the stucco is applied as in your link with an upward motion only (side to side does not do the same job as down does ... side to side only partially sort of maybe gets some stucco down and around the metal lath and into the cups).

The scratch coat is also required to be scratched in, and he did not do that properly either.

The two main failures likely to happen with the stucco job in your link are: a) the metal lath will rust because it is not fully embedded within the stucco; b) the stucco may come loose as the stucco is fully embedded ("keyed" into the lath and the cups of the lath) ... and the brown coat may not fully bond properly to scratch coat which is not properly scratched to provide mechanical bond for the brown coat to grab to.

In your link, watch it and look on the left side of the video ... see that wall he did earlier? See all that metal lath in the stucco? Yeppers, that is likely another failure point as the scratch coat was not applied thick enough (you will not see the metal lath with a proper thickness scratch coat).

That video link shows 'how NOT to apply stucco' ... ... that guy needs .

Originally Posted by Jerry Peck

Robert,

That link shows a stucco job which is likely to fail.

This guy puts it on better, still not quite right all the time, but more right most of the time: https://www.youtube.com/watch?v=zcvVlOMHeEo

The reason for the stucco job in your link will likely fail is that the metal lath (never ever use "chicken wire" - not allowed by code) is that the stucco is supposed to be fully embedded around the metal lath (the metal lath is supposed to be fully embedded within the stucco).

To do that, the stucco needs to be pushed up as it is being applied, then come back down over the stucco with the trowel to force the stucco into the metal lath and fully around the metal lath.

Additionally, the metal lath is to be installed with "cups up", when the stucco is applied properly with the downward pull of the trowel, the stucco is forced down and into the "cups", when the stucco is applied as in your link with an upward motion only (side to side does not do the same job as down does ... side to side only partially sort of maybe gets some stucco down and around the metal lath and into the cups).

The scratch coat is also required to be scratched in, and he did not do that properly either.

The two main failures likely to happen with the stucco job in your link are: a) the metal lath will rust because it is not fully embedded within the stucco; b) the stucco may come loose as the stucco is fully embedded ("keyed" into the lath and the cups of the lath) ... and the brown coat may not fully bond properly to scratch coat which is not properly scratched to provide mechanical bond for the brown coat to grab to.

In your link, watch it and look on the left side of the video ... see that wall he did earlier? See all that metal lath in the stucco? Yeppers, that is likely another failure point as the scratch coat was not applied thick enough (you will not see the metal lath with a proper thickness scratch coat).

That video link shows 'how NOT to apply stucco' ... ... that guy needs .

That is not chicken wire. It is approved for stucco.
17 gauge, self furred stucco netting.
Also the concrete coat was not scratch yet.

Originally Posted by ROBERT YOUNG

SI never used chicken wire, ...

Originally Posted by ROBERT YOUNG

That is not chicken wire.

Your comment is what I was referring to, not the lath he was using - I said to "(never ever use "chicken wire" - not allowed by code)" in reference to your comment about chicken wire.

Also the concrete coat was not scratch yet.

I suspect you are referring the video which runs after the first video and to the scratch coat applied to what looked like a masonry wall (I could see mortar joint lines behind the initial coating), and I suspect that 'initial coating' I just referred to was a dash bond coat. Masonry typically does not require a dash bond coat, concrete requires either a dash bond coat or bonding agent prior to applying the scratch coat.

Stucco is not a "concrete coat", which is why I suspect you are not referring to the stucco which was being applied to metal lath in the first video in your link.

Since the bulge is below the crawlspace vent, I would say the stucco was applied over the foundation wall, and not the wood framing.

- - - Updated - - -

Since the bulge is below the crawlspace vent, I would say the stucco was applied over the foundation wall, and not the wood framing.

Originally Posted by Jerry Peck

Your comment is what I was referring to, not the lath he was using - I said to "(never ever use "chicken wire" - not allowed by code)" in reference to your comment about chicken wire.

I confess, I should not have used the term, chicken wire. It was/is approved stucco net.

Originally Posted by Jerry Peck

I suspect you are referring the video which runs after the first video and to the scratch coat applied to what looked like a masonry wall (I could see mortar joint lines behind the initial coating), and I suspect that 'initial coating' I just referred to was a dash bond coat. Masonry typically does not require a dash bond coat, concrete requires either a dash bond coat or bonding agent prior to applying the scratch coat.

Stucco is not a "concrete coat", which is why I suspect you are not referring to the stucco which was being applied to metal lath in the first video in your link.

Thanks. Just downloaded a PDF on terminology.Much appreciated.

Originally Posted by Jack Feldmann

Since the bulge is below the crawlspace vent, I would say the stucco was applied over the foundation wall, and not the wood framing.

Yes, if so I concur, below a sill. Likely the walkway was not part of the original lot architecture as well. Heavy impervius material will settle. That will trap moisture at the foundation.
Likely the foundation spalled and the parge failed over time so the homeowner hired a "stucco specialist" to apply his unproven, it works until it fails method and guaranty.

Originally Posted by Jerry Peck

Your comment is what I was referring to, not the lath he was using - I said to "(never ever use "chicken wire" - not allowed by code)" in reference to your comment about chicken wire.

Charley B., an astute and highly regarded home inspector at InterNACHI is a stucco trades person. He corrected misused/slag inspectors would use on the MB. Chicken wire being one such term.
I used the term chicken wire incorrectly and he took the time to explain the correct narratives a home inspector should use.
Organic mulch being one term I immediately identified as ten test insulation. It stuck.
Ron Hofford, now a senior staff member and educator, teaches a course I will review/re-certify this month.
Time for more CEU's.

Originally Posted by Jerry Peck

I suspect you are referring the video which runs after the first video and to the scratch coat applied to what looked like a masonry wall (I could see mortar joint lines behind the initial coating), and I suspect that 'initial coating' I just referred to was a dash bond coat. Masonry typically does not require a dash bond coat, concrete requires either a dash bond coat or bonding agent prior to applying the scratch coat.

I thought DASH was ISIS?
I concur, the correct latex adhesives used "as per the manufactures recommendations" add bonding strength.
I took a two step approach. I hydrated concrete or masonry walls, summer and sun being tricky, and watched for over saturation before applying a slurry prior a dash coat. I personally followed manufactures recommendations and watched them fail as well.
I found it useful to observe commercial installers and make note of manufactured products and applications and tools.

Originally Posted by Jerry Peck

Stucco is not a "concrete coat", which is why I suspect you are not referring to the stucco which was being applied to metal lath in the first video in your link.

You are correct.