Thread: Deteioration of CMU foundation wall

"Gravel" material on ground is what has come off block. House is 11 years old and pics were taken inside of crawl space. No signs of water entry. Localized to about a 15' section of wall. Sent pics to a PE I know and he's never seen this. Anyone seen anything like this before / causes?033 (Large).jpg030 (Large).jpg032 (Large).jpg

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Whats on the exterior in this location? Grading, soil type, driveway, exterior wall finish material?

My guess is water even though there is no water coming through and/or bad block.

They look damp to me, but I wasn't there. I have seen this in much older homes, but they had moisture intrusion. The blocks just crumbled.

I have seen block deteriorate like that when saturated with water for long periods of time. Much of it has been old cinder block, but some was concrete block. I never say any that young. Possibly poor quality block or some type of acidic ground water.

BTW, what is the red/orange material. That looks like deteriorated brick.

Originally Posted by Mark Reinmiller

I have seen block deteriorate like that when saturated with water for long periods of time. Much of it has been old cinder block, but some was concrete block. I never say any that young. Possibly poor quality block or some type of acidic ground water.

BTW, what is the red/orange material. That looks like deteriorated brick.

Exterior finish is brick. Grade is fair - sloped away but minimal. Buried downspout in this area. Soil in crawl was dry. Red/orange material is our wonderful soil. Looks odd in the photo.

Buried downspout? That could be the problem either its clogged or the weeper tile is clogged/damaged.

Originally Posted by Raymond Wand

Buried downspout? That could be the problem either its clogged or the weeper tile is clogged/damaged.

Or it goes to an underground drain pipe to a discharge elsewhere. Down here (at least in many parts of Florida) the underground drain pipe goes to what many refer to as 'bubblers' - about a 12" x 12" catch basin which is used for the discharge end.

Because those are intended to catch drainage and direct it to the pipe, they hold water ... and breed mosquitoes ... so I recommend cutting the bottoms out and creating a dry well under where it is placed.

Rain water flows from it and out the 'bubbler', residual water in the pipe and bubbler seeps down into the dry well.

Here is what the VP of engineering from the National Concrete Masonry Association had to say about this:

"First thought may have been sulfate attack, but if it is localized to only a portion of the foundation, unlikely. Given that the degradation is impacting both the units and mortar – unlikely it is a material issue, but something environmental. I’d go through potential chemical exposure with the owner. Is there heavy fertilizer use on the exterior at this location? Do they (or did they at one time) have termite treatment as some of those chemicals are pretty caustic and a little overspray could have resulted in this damage?"