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-   -   Rain seepage stain removal on bare CMU walls and sealing (http://www.houserepairtalk.com/f17/rain-seepage-stain-removal-bare-cmu-walls-sealing-13677/)

Peipei9 03-29-2012 05:02 AM

Rain seepage stain removal on bare CMU walls and sealing
 
2 Attachment(s)
Hey all! Nice message board here.

I am a home owner with a problem and looking for advice. I live in a condo and a number of us home owners are having this issue. We are about to go all law-suity on the builder and architect over this.

My condo has brick walls. The exterior is supposed to be sealed with a transparent sealant and the interior is bare. These were built in 2008, Arizona desert environment.

Unfortunately, the sealant job did not hold and water is coming through the exterior walls during heavy rains, which has happened three or four times in the last two years.

You can see pictures of this here. Some of these pictures show water coming through, and some show the stains left over afterward. Beware the click-through spam.

http://www.opendreams.net/jesse/images/wmb20120329/

The sealant, which has been applied twice, is apparently BASF Enviroseal 7, which is a water-based silane/siloxane sealer.

The architect's current theory as to why the sealant isn't holding is that when the walls were erected, they were sandblasted heavily and the mortar was raked rather than left flush or concave. Because of the opportunity of the raked shelf on the block, the water is just sitting in the joints and getting absorbed in. The sealant was sprayed on, and with such a surface type, it is hard to get the sealant applied to the raked shelves.

I was told that a BASF rep has come out and run tests (rhylo tube test?) on the walls and agrees that water is going right through. In some areas it is going through the block itself, but mostly it's shooting straight through the grout lines.




My two questions are:

1.) How do we treat the stains?

2.) Any recommendation for sealing the walls?



We are currently negotiating with the builder and architect that they will have the grout lines filled with a specific product designed for this. A significant concern of ours is the natural block look, so we don't want to paint the walls. Any sealer will need to be transparent, or blend in with the block and grout. The first thing the builder wanted to do was just paint the walls gray. Basically, they wanted to take the cheapest way out possible (I know, shocking). Once we started spreading pictures around town and the architect became involved, they got a little more serious.

We are not sure if the company that applied the sealant did it right or not. We are still getting info on that and have a meeting with the BASF rep next week.

We are also looking to hire a 3rd party expert to give us some opinions.

As for the stains, that's where you guys can really help. What will and won't work on this? Sand/walnut blasting? Acid wash? We have no clue.

I will check back here over the next couple of days. Any advice or comments would be appreciated.

oldognewtrick 03-29-2012 06:20 AM

I'm seeing water stains and effervescent at the top of the block. I'm also seeing water stains on the corrugated metal above, are you sure the water is not coming down from above?

Also, what is on topside of the metal ceiling?

mudmixer 03-29-2012 07:39 AM

Very confusing information is provided.

The post title lists CMUs as being "bare" (inside or outside?), while the information provided refers to brick.

Is the wall a composite wall (brick and block) or is it a single wythe (block) wall?

There is no question that there is water in the walls that is rusting the floor system and the cores of the block walls have moisture. The pattern of the moisture on the interior surface is quite strange and does not follow the pattern for a wall with minimal vertical reinforcement, but that is just speculation and may occur because of the construction methods.

Raked joints on an exterior wall (brick or block) is not really a water resistant joint and you do have some seasonal "monsoon" rains. It is a bad architectural detail that is difficult to repair and get a good bond for the patched portion.

If the wall is actually a block and brick wall, the is no air gap between the brick and block to allow ventilation and drainage and the gap also eliminates the pressure differential that can force moisture into the interior wythe of the wall.

The sealer material is acceptable, for the short term, but spraying severely limits the effectiveness and usually the applicator does it "by eye" and has "waterproofing" left over when he is done. So sealersa deteriorate more quickly in hot climates.

Dick

Peipei9 03-29-2012 04:27 PM

Quote:

Originally Posted by mudmixer (Post 70836)
Very confusing information is provided.

The post title lists CMUs as being "bare" (inside or outside?), while the information provided refers to brick.

Is the wall a composite wall (brick and block) or is it a single wythe (block) wall?

There is no question that there is water in the walls that is rusting the floor system and the cores of the block walls have moisture. The pattern of the moisture on the interior surface is quite strange and does not follow the pattern for a wall with minimal vertical reinforcement, but that is just speculation and may occur because of the construction methods.

Raked joints on an exterior wall (brick or block) is not really a water resistant joint and you do have some seasonal "monsoon" rains. It is a bad architectural detail that is difficult to repair and get a good bond for the patched portion.

If the wall is actually a block and brick wall, the is no air gap between the brick and block to allow ventilation and drainage and the gap also eliminates the pressure differential that can force moisture into the interior wythe of the wall.

The sealer material is acceptable, for the short term, but spraying severely limits the effectiveness and usually the applicator does it "by eye" and has "waterproofing" left over when he is done. So sealersa deteriorate more quickly in hot climates.

Dick

Hi! Thanks for your questions. Sorry that I a not a masonry guy. I probably used wrong terminology.

The floor inside is polished concrete and the ceiling is that metal. It's a poured slab on the 2nd floor.

The wall is single block width and is a load bearing wall for two floors above it. I am sure that they filled it every couple of feet or whatever was required. I get the impression that they only filled every couple of feet or so.

Peipei9 03-29-2012 04:29 PM

Quote:

Originally Posted by oldog/newtrick (Post 70833)
I'm seeing water stains and effervescent at the top of the block. I'm also seeing water stains on the corrugated metal above, are you sure the water is not coming down from above?

Also, what is on topside of the metal ceiling?


That metal has the 2nd floor slab poured into it. It is solid.

Actually, you are right that there is water getting into the top too. The flashing is bad. The pictures you are looking at are from several different condos and one of them has bad flashing where rain water is getting in from the top of the block. The stucco company is already scheduled to come out and replace the flashing, which they have done on one unit already. So, some of the water is coming directly through down low, and some is seeping in where the flashing is supposed to prevent that on top.

oldognewtrick 03-29-2012 06:38 PM

Can you show a picture of the wall flashing on a repaired unit and one that has not been repaired?

Peipei9 03-29-2012 08:15 PM

2 Attachment(s)
The first picture is an unaffected unit. The flash sticks out about an inch. The second picture shows the flashing is flush with the stucco, so the water is not deflected and it runs down the stucco and directly onto the brick.

I don't have a picture of the repaired wall yet, but it looks just like the unaffected unit. The difference is that the flashing was flush with the stucco wall vs sticking out an inch and thus deflecting runoff.


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