# Exterior CMU wall leaking



## gene0108 (Sep 11, 2008)

I have a new exterior CMU wall that was sprayed with 1 coat of Pro Block Primer and backrolled with Pro Block Primer. Following the Pro Block Primer, 2 coats of Sherlastic Paint was applied. The Sherlastic was sprayed and backrolled.
I am an Architect and I cannot figure out how the water is getting in. If you hold a garden hose and let the water run down the wall continuous for about five to ten minutes you start to see the water comming into the building at the base on the interior.

Help, I do not know how to solve this problem.

Thanks in advance for the help.
Gene


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## TooledUp (May 17, 2008)

Sounds more like a construction problem to me. Paint might hold water back for a while but it doesn't stop leaks. You can't rely on paint to make a place watertight. Have you got expansion joints? Is the interior floor level below ground level? Is it a cavity wall? If so, is the ventilation cover adequate? What about facia and soffit boards? Are they sealed? Shouldn't an architect know these things?

Edit: I've been thinking about this one - Are you sure that your waterproofing is done right? Got the correct waterproof membrane on and installed properly?


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## gene0108 (Sep 11, 2008)

There is a 1-1/2" brick ledge for this wall. It is a single Wyth wall. Single 8" cmu wall no interior wall. This wall is only 4' high with metal building wall panels on metal studs above this. If you cover the cmu wall with plastic and spray water on the windows and the metal wall panels above the 4' cmu, along with spraying water on the roof, nothing leaks. So we came to the conclusion it is the cmu wall below 4' that is letting the water in. There is a bond beam at the top of the wall. The cmu wall is filled with concrete at 4'-0" on center.


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## TooledUp (May 17, 2008)

No waterproof membrane? You say it's a single wall - Is it just exposed blocks on exterior? I'm presuming that they're grouted? Grout alone won't waterprooof anyway. You can use a tar sealer on it but a membrane and outer-covering is best. 

I'm presuming it's a commercial property when it's only single wall?

Construction isn't my thing really - Just picked a few things up over the years...


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## gene0108 (Sep 11, 2008)

It is exposed block inside and out. I called Sherwin Williams and they said to use Loxon with two coats of paint. That's all. That will waterproof my wall as per the salesman I talked to.
Thanks,
Gene


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## TooledUp (May 17, 2008)

gene0108 said:


> It is exposed block inside and out. I called Sherwin Williams and they said to use Loxon with two coats of paint. That's all. That will waterproof my wall as per the salesman I talked to.
> Thanks,
> Gene


Cool. Did they give you any indication on how long it would last?


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## gene0108 (Sep 11, 2008)

No they did not. I just spoke with a Sherwin Williams Rep that is in my area. He will meet me at the jobsite this afternoon. So I will give you the answer when I get back. I will also give the answer as to what you are SUPPOSE to paint new concrete block with.
Thanks for your help.
Gene


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## Dmax Consulting (Jul 22, 2008)

I used to be a Sherwin-Williams rep. The Loxon is supposed to stop wind-driven rain on sound substrates. If there are big gaps or heavy water, the loxon isn't going to stop it. You need to use a true waterproofer like ugl drylock or may something even heavier.


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## TooledUp (May 17, 2008)

gene0108 said:


> So I will give you the answer when I get back. I will also give the answer as to what you are SUPPOSE to paint new concrete block with.
> Thanks for your help.
> Gene


You can paint exterior block with any exterior quality wall paint. The issue is waterproofing it. I agree with Dmax - If it's the 'holey' type block then you need something realy heavy to cover and fill them.
Why weren't solid, heaweight blocks used? Wait, don't tell me. I bet the architect specified them :whistling2: :jester:


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## gene0108 (Sep 11, 2008)

You are correct. The Architect specified them. Which would be me. I specified Lightweight block vs. Normal weight block. I just got back from the jobsite with the rep. They did use the correct products: Block Filler and two coats of paint.
The problem was they did not use enough paint. There are still thousands of pin holes in the block. The rep did the water test with the thing that looks like a smoking pipe. You pour water in the top and let it sit in there for twelve hours.......well we could not keep water in it. As soon as you stopped pouring the water in the test tube it went right into the block.
So we are going to let the block dry out and then paint the block again with the elestomeric coating.
As an architect I wish I knew more about painting. Learned alot today as to what to look for after the block is painted. There should be very few pin holes showing thru.
OH I also learned that after you apply the block filler you should not find many pin holes. 
The painter will re-paint the wall for free.
Sorry for the long post.


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## timhag (Sep 30, 2007)

gene0108 said:


> The painter will re-paint the wall for free.
> .


*Why for free? You are the Architect. Was it his fault that this happened? What kind of respect do you have for painters? You come to the a professional PAINTERS forum and ask for advice about a problem you caused and you expect this painter to do it for free. BULLSH*T brother.*


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## Tonyg (Dec 9, 2007)

timhag said:


> *Why for free? You are the Architect. Was it his fault that this happened? What kind of respect do you have for painters? You come to the a professional PAINTERS forum and ask for advice about a problem you caused and you expect this painter to do it for free. BULLSH*T brother.*


 
Whoooaaaa Tim,

I kinda agree that the painter did not do his job. I believe "water proofing" CMU means leaving like 10 pin holes per square foot or something like that. This guy applied block filler and two more coats of elastomeric and it is thin enough to have holes like that? You don't have to have a solid block wall to have a water proof seal. What was speced for this seemed appropriate to me. It also seemed like he had enough respect for painters to come here and asked what went wrong and how it could be fixed. 

If an inspector walks up and tests the mil thickness only to find it has half the paint on a substrate how is this the architects fault? Its not, the painter either skipped a coat or thinned it down.


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## timhag (Sep 30, 2007)

Tonyg said:


> Whoooaaaa Tim,
> 
> I kinda agree that the painter did not do his job. I believe "water proofing" CMU means leaving like 10 pin holes per square foot or something like that. This guy applied block filler and two more coats of elastomeric and it is thin enough to have holes like that? You don't have to have a solid block wall to have a water proof seal. What was speced for this seemed appropriate to me. It also seemed like he had enough respect for painters to come here and asked what went wrong and how it could be fixed.
> 
> If an inspector walks up and tests the mil thickness only to find it has half the paint on a substrate how is this the architects fault? Its not, the painter either skipped a coat or thinned it down.


Appears that this "Architect" is in control of the situation. I bet the painter (if professional) would have given his 20 cents worth and this "Architect" shut him down. I would have walked away from this guy if I knew a job would have not worked and some Architect was over riding me. Man up Mr. Architect, if you are in the wrong. Pay Sev for redoing the work you screwed up.


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## gene0108 (Sep 11, 2008)

I will always be the first to admit when I was wrong. I fail to see where I was wrong in this situation. I could not figure out how the water was getting into the building. I met the Sherwin Williams Paint rep at the site. He, not I, concluded that there was not enough paint on the wall to cover up the pin holes in the CMU wall. 
I know you are thinking I am in the wrong for specifying the wrong CMU. I just finished bidding a 107,000 sq ft school using Normal Weight Block. I had a few contractors call me and ask me to change it because they were not used to using Normal Weight block. Two Contractors in particular said they had not used Normal Weight Block in 20 years.
I fail to see where I was wrong when I specified lightweight block when 99 percent of the block work in this area is with Lightweight Block. The CMU guys do not like handling these blocks. Lightweight block is 26 lbs per block and Normal Weight Block is 46 lbs per block.
And when the painter bid the job did he not know what he was bidding on? Did he not read the plans to see that it was built with Light Weight Block?
Thanks,
Gene


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## timhag (Sep 30, 2007)

gene0108 said:


> And when the painter bid the job did he not know what he was bidding on? Did he not read the plans to see that it was built with Light Weight Block?
> Thanks,
> Gene


Then accept my apology for feeling that way. But you sure were a dumb ass for hiring someone who doesn't know what he/she is doing. :thumbsup:


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## gene0108 (Sep 11, 2008)

Oh, one more thing. You are correct. On Sherwin Williams ConFlex Elastomeric coating it is 10 pin holes per sq. ft.
Again guys thanks for your help. I have alot to learn about paint/coatings. I asked the question here because you guys deal with painting everyday. You are the experts, not me.
I'm glad I found this forum. Hope you did not mind me asking the question. Just trying to learn.
Thanks again,
Gene
In Louisiana


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## timhag (Sep 30, 2007)

gene0108 said:


> Oh, one more thing. You are correct. On Sherwin Williams ConFlex Elastomeric coating it is 10 pin holes per sq. ft.
> Again guys thanks for your help. I have alot to learn about paint/coatings. I asked the question here because you guys deal with painting everyday. You are the experts, not me.
> I'm glad I found this forum. Hope you did not mind me asking the question. Just trying to learn.
> Thanks again,
> ...


Welcome to the forum from Pittsburgh Pa.


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## gene0108 (Sep 11, 2008)

As an Architect we do not hire the subs. We only hire the General Contractor. It is the General Contractors responsibility to hire all of the subs. This was a public job. I had no say-so as to whom the painter was. And I know that the Owner of the Company might know how to apply a coatings but he cannot always depend on the guys in the field holding the brush.
I am just thankful that the painter will reapply the coating at no additional charge to my client.
I will be much more aware of this situation when it comes time to paint all of the block walls in a 107,000 sq. ft. school.
I just could not believe that all of that water in the building was comming directly thru the block wall that had three coats of paint on it.

Thanks,
Gene


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## gene0108 (Sep 11, 2008)

This is the response I just received by e-mail from the Sherwin Williams Headquarters. I sent them an e-mail asking them what to use to paint a new exterior CMU wall.

Hello,


Typically we would recommend that you prime this surface with the Loxon
Masonry Conditioner and follow with 2 coats of the Super Paint Exterior
Latex paint.


All new surfaces must cure for at least 7
days. Remove all form release and curing
agents. Pressure clean (minimum
2100 psi) to remove all dirt, dust, grease,
oil, loose particles, laitance, foreign material,
peeling and defective coatings,
chalks, etc. Allow the surface to dry before
proceeding. Repair cracks, voids,
and other holes with ConSealT Patches
and Sealants.

There are always a variety of conditions that need to be discussed and taken
into consideration when specifying coatings. Please contact your local
Sherwin-Williams Paint Store manager for a complete project recommendation.


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## Tonyg (Dec 9, 2007)

Super paint as a water sealer on masonry? :no:

Too thin unless your first coat was extremely thick and well applied. Although, I have not used the Loxon Masonry Conditioner. I do remember the days when block filler was mixed from a powder and applied with a scrub brush or a 90lb roller.


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## tsunamicontract (May 3, 2008)

that seems strange as the conditioning masonry primers are typically meant for weathered, chalky masonry or previously painted (and failing) masonry. And superpaint? I would think that would not work unless there was block filler applied first. 10 pinholes per square foot is the standard in waterproofing, not exclusive to a SW product. So what ever you apply that is what needs to be achieved. I believe PPG owns Perma Crete which has a good line of masonry coatings.


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## Bender (Aug 10, 2008)

Good to know there is a difference in block. Thank you Gene:thumbsup:


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## TooledUp (May 17, 2008)

Imho, the whole 'lightweight block' thing for a finished wall seems to be a real bad building practice. Yeah, fine if you're going to put an exterior skin over it, but for a finished wall..? Why?

It's going to need regular maintenence over its lifespan and be dependant on a layer of paint to keep it watertight.

Why not use a heavyweight block or even brick in the first place? I know that the building regulations here wouldn't allow it. Surely the extra cost in the constant maintenence involved over the years (and potential leaky disasters) will far outweigh a nominal extra in laying heavyweight/solid blocks?


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