Basement wall comes crumbling down.

paperfist

Diamond Member
Nov 30, 2000
6,539
286
126
www.the-teh.com
Well not totally, but each year this one corner of my cinder block basement wall leaves a pile (maybe a quart) of cement dust on the floor. There's never any detectable water and it seems pretty dry down there. There had been previous patches done but that was 15 year ago by the previous owners.

I'm thinking of spray foaming the walls this year (the rest of the house is done) and I'm a little worried if I do that the cement will continue to crumble, but without me being able to see it.

Is there something I can use to parge over the existing blocks to keep it from crumbling? It would be nice to know why it's crumbling in the first place.

Thanks for the help!
 

mrblotto

Golden Member
Jul 7, 2007
1,639
117
106
what part of the corner? Top, bottom, middle? Do you see any cracks? Are the cinder blocks painted? If not, are any spots darker than the surrounding area? Any outside faucets nearby?

cliffs:
yeah, pics please :)
 
  • Like
Reactions: paperfist

paperfist

Diamond Member
Nov 30, 2000
6,539
286
126
www.the-teh.com
I'll get some pics!

hmm tree roots... Well there were some monster 80' pines out front not to far from the house. They heaved the sidewalk, but not sure they would grow under the house looking for water? The water service is on the opposite side of where the problem is.

There is another mini monster tree on my neighbors (pine too) property that's 15' from my basement wall. It's heaving my pavement driveway which butts up to my basement wall. Not sure why I didn't think it could pose a problem. A few years ago I thought it was a water issue and had the driveway built up to pitch further away from my basement wall and I installed gutters, but that never seemed to fix the issue.
 

mrblotto

Golden Member
Jul 7, 2007
1,639
117
106
D'oh! My first guess is something is pushing/exerting force on that part of the wall. Either runoff from the roof/wherever making the soil semi-liquid. I wouldn't think a tree that had (presumably) been cut down would initiate such a problem, unless said problem was there while the tree was still up/growing

How far down would you have to dig to have a look-see? A couple feet? From the looks of it the 'problem' existing at or very near ground level

You wanna catch this as early as possible. As a related/maybe-not story:

My father had purchased a 100+ yr old home downtown for us to live in. The foundation was stone - just flat rocks piled onto each other - with no binding agent (ie concrete) in between.
Needless to say, there was water leakage, so he decided to dig out a 'trench' (with my help) some 8 foot deep X 2 feet wide along the affected wall so concrete could be poured in, thus sealing it up all nice and neat.

So, the day arrived when the big 'ole cement mixer-mobile came, and start unloading it's contents into the trough. It poured......and poured..........and poured. At one point, the 'level' of the concrete stopped rising. The cement mixer dude remarked something like 'hey, this is taking a LOT of concrete!

So, my dad went into the basement. Much to his chagrin, the pressure from all that concrete had pushed out a few of those flat rocks, and concrete was now pooling in the basment lol!

Much panic ensued, then a bucket brigade was formed, the hole plugged, and all was right with the world (eventually).

Good luck, and keep us updated!
 
  • Like
Reactions: paperfist

Dranoche

Senior member
Jul 6, 2009
302
68
101
Hard to tell in the first pic. Looks like it's on a corner, could have been damaged prior to or during installation. No idea why it may have just now come apart. Has that spot slowly deteriorated or did a larger chunk fall off? Second pic looks like deterioration of the masonry units at the bottom, probably due to freeze/thaw a long time ago or some type of chemical. The faces of the blocks in the upper portion of the second pic look pitted, and some spots look like there may have been paint, so I can't tell from the pics if there is any efflorescence. You said things look pretty dry, but the units can soak up a lot of water and then dry pretty quickly. You can check each day for several days after a heavy rain storm and see if you can identify any damp areas or locations with new staining. Might be worth involving a structural engineer or a materials engineer. If it ends up being nothing then at least you have peace of mind.

Third pic looks like a shrinkage crack along the mortar joint. Unless any of the units appear to have shifted along this plane, I wouldn't be concerned with that.
 
  • Like
Reactions: paperfist

paperfist

Diamond Member
Nov 30, 2000
6,539
286
126
www.the-teh.com
D'oh! My first guess is something is pushing/exerting force on that part of the wall. Either runoff from the roof/wherever making the soil semi-liquid. I wouldn't think a tree that had (presumably) been cut down would initiate such a problem, unless said problem was there while the tree was still up/growing

How far down would you have to dig to have a look-see? A couple feet? From the looks of it the 'problem' existing at or very near ground level

You wanna catch this as early as possible. As a related/maybe-not story:

My father had purchased a 100+ yr old home downtown for us to live in. The foundation was stone - just flat rocks piled onto each other - with no binding agent (ie concrete) in between.
Needless to say, there was water leakage, so he decided to dig out a 'trench' (with my help) some 8 foot deep X 2 feet wide along the affected wall so concrete could be poured in, thus sealing it up all nice and neat.

So, the day arrived when the big 'ole cement mixer-mobile came, and start unloading it's contents into the trough. It poured......and poured..........and poured. At one point, the 'level' of the concrete stopped rising. The cement mixer dude remarked something like 'hey, this is taking a LOT of concrete!

So, my dad went into the basement. Much to his chagrin, the pressure from all that concrete had pushed out a few of those flat rocks, and concrete was now pooling in the basment lol!

Much panic ensued, then a bucket brigade was formed, the hole plugged, and all was right with the world (eventually).

Good luck, and keep us updated!

Wow hats off to dad, he knows how to undertake a project! Glad someone caught the ousted rocks before the whole basement was flooded with concrete.

Well the wall of the foundation with issues is paved above for the driveway. So digging would be a major undertaking and the driveway isn't quite ready to be replaced.
 

paperfist

Diamond Member
Nov 30, 2000
6,539
286
126
www.the-teh.com
Hard to tell in the first pic. Looks like it's on a corner, could have been damaged prior to or during installation. No idea why it may have just now come apart. Has that spot slowly deteriorated or did a larger chunk fall off? Second pic looks like deterioration of the masonry units at the bottom, probably due to freeze/thaw a long time ago or some type of chemical. The faces of the blocks in the upper portion of the second pic look pitted, and some spots look like there may have been paint, so I can't tell from the pics if there is any efflorescence. You said things look pretty dry, but the units can soak up a lot of water and then dry pretty quickly. You can check each day for several days after a heavy rain storm and see if you can identify any damp areas or locations with new staining. Might be worth involving a structural engineer or a materials engineer. If it ends up being nothing then at least you have peace of mind.

Third pic looks like a shrinkage crack along the mortar joint. Unless any of the units appear to have shifted along this plane, I wouldn't be concerned with that.

It's near the corner. Sorry I have a shelf shoved in the corner so couldn't get a great pic.

It's been falling apart for a while, but now that I want to spray foam it I want to address it because once it's foamed I won't be able to keep tab on the issue.

I don't really see any efflorescence. Yes it was painted and that's slowly been coming off.

hmm wonder if I can put a moisture meter on it?
 

Dranoche

Senior member
Jul 6, 2009
302
68
101
There are moisture meters but they're expensive and accuracy will be questionable as the reading will only provide an indication of moisture in the outer portion of the concrete. You would need probes installed deeper to really get a good reading. If you could find a way to reliably secure a couple calcium chloride kits to the wall you could measure vapor transmission, and use a hygrometer to check humidity as well in the basement. Then install a kit and use the hygrometer elsewhere in the house to compare. Might give a potential indication of a moisture issue behind the wall. How old is the house?
 

jmagg

Platinum Member
Nov 21, 2001
2,172
442
136
For starters, i'd wire brush it until solid, and paint a slurry of portland and water on the loose spots and see if it holds up.