||03-29-2012 05:02 AM
Rain seepage stain removal on bare CMU walls and sealing
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.
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.