Stucco over CMU question - Contractor Talk - Professional Construction and Remodeling Forum

CJKarl · 08-31-2009, 07:33 PM

I get a call from a guy about a stucco problem. Here it is.

It's about a 10 year old free standing block garden wall. 6' tall with a stone coping. Customer says he had a few spots, couple feet in diameter cracking and falling off. He had a stucco guy come back in last spring and chip off the loose stuff and re-apply stucco, then paint with some high-end flexible paint.
He also cut out the joints in the coping and it appears, caulked them. The whole repair looks neat and tight...but,
In the spots that he said had the problems, you can now see a slight bulge starting right on the head and bed joints of some of the block. I don't see how water would be getting in there. The repair looks real tight. I don't know if this happened as they were applying the repair (soaking wet joints?) or if it just started a couple weeks ago as the owner stated.
Any of you stucco master know what may be going on here?
No it's not on wire or foam.
I told him he may have to just cover it up with an EFIS type system.

CJKarl · 09-01-2009, 03:20 PM

Nutt'in??

Tscarborough · 09-01-2009, 03:53 PM

The only thing an think of is efflorecence under the repair blistering the coating, but it generally will stop if the water intrusion stops. Sprinkers?

concretemasonry · 09-01-2009, 04:25 PM

Does the coping have a positive drainage, overhang and a drip? Is it the same coping that was there initially and during the first surface failure?

If not the water could just follow the surfaces down and feed moisture into the wall than can destroy a wall surface in many ways depending on the type of climate.

bwalley · 09-01-2009, 05:23 PM

Quote:

Originally Posted by CJKarl

I get a call from a guy about a stucco problem. Here it is.

It's about a 10 year old free standing block garden wall. 6' tall with a stone coping. Customer says he had a few spots, couple feet in diameter cracking and falling off. He had a stucco guy come back in last spring and chip off the loose stuff and re-apply stucco, then paint with some high-end flexible paint.
He also cut out the joints in the coping and it appears, caulked them. The whole repair looks neat and tight...but,
In the spots that he said had the problems, you can now see a slight bulge starting right on the head and bed joints of some of the block. I don't see how water would be getting in there. The repair looks real tight. I don't know if this happened as they were applying the repair (soaking wet joints?) or if it just started a couple weeks ago as the owner stated.
Any of you stucco master know what may be going on here?
No it's not on wire or foam.
I told him he may have to just cover it up with an EFIS type system.

It is wicking water up through the footer, wall footers don't have a vapor barrier in them and they wick up moisture, that is why elastomeric paint on all 3 sides are a bad idea.

CJKarl · 09-01-2009, 09:18 PM

The cap has an 1 1/2" over hang, as I said before, the cap joint repair looks real tight.
Water could be wicking up from the ground, but it was redone in the spring and we haven't had any freezes yet.
Thanks for the good point about the wall being totally sealed. I'll try to get some pictures this week. I told the guy to wait and see what happens. If it's going to get repaired again, waiting isn't going to hurt.

bwalley · 09-01-2009, 09:33 PM

Quote:

Originally Posted by CJKarl

The cap has an 1 1/2" over hang, as I said before, the cap joint repair looks real tight.
Water could be wicking up from the ground, but it was redone in the spring and we haven't had any freezes yet.
Thanks for the good point about the wall being totally sealed. I'll try to get some pictures this week. I told the guy to wait and see what happens. If it's going to get repaired again, waiting isn't going to hurt.

The water is not coming in from the top of the wall, it is coming in through the footer.

It isn't rocket science, concrete wicks moisture from the ground and when you encapsulate it with elastomeric coatings you get these kinds of problems.

With walls you have more problems with mositure wicking up the wall than coming in through the sides, if you want to keep water from coming in from the top, use elastomeric on the top but not the front and back side of the wall.

CJKarl · 09-02-2009, 05:07 PM

Quote:

Originally Posted by bwalley

The water is not coming in from the top of the wall, it is coming in through the footer.

It isn't rocket science, concrete wicks moisture from the ground and when you encapsulate it with elastomeric coatings you get these kinds of problems.

With walls you have more problems with mositure wicking up the wall than coming in through the sides, if you want to keep water from coming in from the top, use elastomeric on the top but not the front and back side of the wall.

Thanks bwalley, so pretty much the guy is fawked?

I'll tell him to EFIS it....and let his grand kids worry about replacing the wall.

bwalley · 09-02-2009, 07:17 PM

Quote:

Originally Posted by CJKarl

Thanks bwalley, so pretty much the guy is fawked?

I'll tell him to EFIS it....and let his grand kids worry about replacing the wall.

Not sure if EFIS would fix it or not but if you can get the front and backside of the wall stripped of the elastomeric coating, fix the wall, paint it with a paint that breathes, like a satin or a flat paint, it should be OK, it is not a bad idea to coat the top of the wall and maybe 6"-12" down the front and back from the top with elsatomeric, it will keep water that sits on top of the wall or gets on there by rain from soaking into it.

DJ9222 · 09-03-2009, 04:41 PM

I agree with my fellow masons that the moisture is coming up thru the footing, one solution might be to put french drains on the front and rear to get the water away from the wall, then you might be able to stucco again with no problems.........
Good luck.....

Red Adobe · 09-03-2009, 09:53 PM

I have to wonder if that small of an area had some kind of oil or other uncompatable on the block.....

I did some plasterin in my 20s and i know EGG will cuase all kinds of hell.

We sprayed all tools with wd40 and sometimes it got on things it wasnt suposed to with new guys who didnt let it dry before loading the hawk

I got a delivery of blocks for a foundation awhile back that had road grime of an oily nature all over the front of the first pallet ( i marked em and made sure the oily side went to the inside )

It may not be an actual water problem is all im thinkin......