Thread: Concrete Porch Crack Shift

Yes I am a newbi,
I did not see any deflection in the interior wall, or ( sub floor (5' clearance root cellar) Sub floor 2x6 t&g with ends facing direction of the crack) I believe this is a floating, or at least not attached to the concrete block foundation wall or concrete block porch surround. Question is what would cause half to shift out like this? There is no heaving lifting up porch floor is level and front of slab line looked straight. I think the image looks worse than looking at it in person. House built in 1972 commercial truss 2x4.. metal supports on ends of porch crack in center ? Also possible cracking on brick joint?
I just want to report it properly. Just a small crack could refer to engineer but do not like passing the buck.

Leslie “Darryl” Piatt
OCHI 1475
CCB 193445
NACHI 11031413

63627 N Olive Rd
Coos Bay, Or 97420

541-888-0270



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Front porch structure appears to be settleing, more than likely due to downspout drainage on the left front corner.

Seal the crack and Monitor for further settlement and repair if crack continues to expand.

Downspout should be directed away from the area at least 15 feet.

Childproof railings are recommended.

Darryl, These structured typically have minimal footings and are filled with dirt and construction debris.
The downspout is always suspect.
Even though the surface level is below height that would require railing it is still a good idea to recommend one.

All the downspouts are hooked into Drainage System Pipes, I did not test them or dig them up to see if they are solid or perf. I did recommend they test as there is some moisture phosphorescence on concrete block in Crawl Space and Daylight basement. (as well as recommending a french drain on Daylight basement side)

That's good, but were they always? maybe the present owner installed them after his inspection.
So now you add, Consult with owner as to when underground drains were installed and if it was related to the settlement issue.
Alot of info can be aquired from a homeowner if you ask the right questions.
And they MUST answer truthfully or suffer the wrath of

T-1-11 wood siding does not stop above porch slab, probably leakage and associated wood decay to wood siding and framing.

Thank you for the help and information. Porch is on the East side of home and has a full guttered roof system clear over it. Here on the coast rains mostly come out of the South West So East is pretty well protected, I did not observe any decay on the T-1-11.

If it got real cold here I would think it could be from freezing. Or possibly an earth quake.
But those are just guess's

I have already submitted the report. Stating observations and Recommend further investigation which in my declarations page states and means by a professional in that field.

Thanks again

The concrete appears to be painted. I wonder if the the pour was done in two stages, creating a 'cold joint' ? The crack looks pretty straight. The paint may be hiding different colored concrete mixes, making it uniform in appearance.

Ian

That could be it, I had only noticed the little uneven portions not the overall straightness of the line.

But what could make it shift that 1/4 even if it was a cold joint. Might be the fill expanding, or the house settling and pressure from the metal decorative supports, I do not think it would get enough moisture against the house to cause decay/swelling has a 6 plus foot roof to where that house siding is. Anyway I pointed it out and recommended investigation.
Thanks

Based on the pictures I don't think that settlement is the problem. What is supporting the concrete slab? Is there wood framing below? If the slab is supported on wood framing with plywood sheathing perhaps the crack occurs over a plywood panel edge that was not properly supported.

I'm from the concrete industry. The straight crack could indicate a foundation wall underneath intended for a smaller porch or the lack of rebar throughout the slab.

Is that concrete original? I see what looks like blue concrete primer. What is it poured on top of? What is below that crack... a joint? I also see a horizontal crack in the morter, what is going on there?

Could be it's straight because a POW (point of weakness strip) was put in the concrete when it was poured. Is it about in the center of the slab?

Steve
It dos look to be original to me and just concrete paint. As I said in the Original post and still believe it has concrete block done in a proper surround, same as house foundation and other porch on South side (not brick faced with no cracks in block or slab,

I did notice decorative brick mortar has cracking right under slab as well. Could these be from settling of the brick possibly not using brick tie's and not a proper footing for them? Shrinking?


Good pictures can point out so much, from a different angle, close ups and lighting with flash, after getting home.

As Wayne pointed out, and have done myself as a mason years back, these are normally filled with rubble all job site clean up, back fill dirt, whatever the mason can find. This might have soaked up water as there are plants all across the front within a couple of feet and shifted.Yard dos slop away from front of home to roadway that is at least 8 feet below the Slab

I think the thought of separate pours without re bar is likely and center support wall might be part of the issue as well.

Here are some more images of Basement wall on inside and South East Support corner showing downspout. Which could have been added anytime. or failed and repaired, Image 1891 is of South Wall not wall opposite. 1892 is proper opposite inside

Thanks all again.

You may never know the true cause of the crack without being able to view from directly underneath and taking core samples - both extremely unlikely. Zooming in on the original crack pictures, I see parallel trowel lines about 4" from the concrete edge on the concrete to the right of the crack. The lines are not visible to me (not in the pic. anyway) to the left of the crack. Though the finish may have been attempted at the same time, the 'left' concrete may have been in a much further advanced stage of curing if poured first - consequently less distinct trowel marks were left. If, as someone else surmised to a lack of through rebar and/or net, then a weak joint would occur at that point. Some shifting or settling of the supporting foundation could well result in what you see, including the horizontal mortar joint failure.

Of course is largely conjecture based on what I do and don't see in the pics. and resulting possibilities. It does not appear to be caused by inadequate drainage or moisture issue to me, though clearly some dampness is striking through - as indicated by the efflorescence on the basement walls. That may due to the crack itself, permitting run-off to seep below grade and into the block wall. Sealing the crack with concrete/mortar mastic might eliminate that water intrusion source.

It's difficult to assess future consequences, progression or hazards but at least identifying it in your report and making suitable recommendations is about as far as you need go. Overall, good topic, nice pics and interesting thread. Thanks.