Thread: Stucco Stains

Hi,

I've come across a 13 yr old home with black stains on the stucco originating from the bottom corners of vinyl windows and where the eavestrough meets the wall and chimney chase. There are also other stains (dark brown) along the chimney chase (see attached photos).

I've read articles that say these types of stains are from broken down tar paper or wood particles (caused by years of water penetration) but I've also read other articles that claim such stains can simply be from airborne contamination (I have doubts that this is simply staining from dirt or pollen).

Does anyone know the most likely cause of these stains?

Thanks.

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It appears from your photos it maybe moisture getting in behind the stucco. I use a disclaimer statement because of all the problems this type of exterior wall cladding causes.

Ian, one other thing to consider is the limited downspouts on this house. Looks like a large amount of roof run off into one downspout. If the gutters are over whelmed they will wet the walls. I can't tell if kick-out flashings are installed. The lack of correct flashing can also show up as staining.

The stains at the bottom corners of the windows may be where the window drain openings are?

I guess this is EFIS as I don't see any control joints? All the more reason for disclaimers and recommending further investigation.

Now isn't is strange how the problems seem to be showing up in the same locations as EIFS problems?

I wouldn't be a bit suprised if there is no diverter (kickout) flashing where the roofline ends in the vertical wall. Is the chimney masonry, I would guess it's a wood.

I don't see a bit of sealant around the window frames, and the windows, well, most window manufacturers recommend a 1/2" isolation joint, properly sealed. I see no flashing either.

Without hesitation, you should recommend a Certified Stucco Inspection.

North and East sides of the house.

The days of zinc coated (galvanized) and copper flashing has passed.
Back in the day such was used for window pans, dams, flashing. We believed in drip edges too.

Betting loonies to donuts neither was used, but the sticky black self-adhering membrane for "flashing".

Zinc and copper oxides deter blue-green algae which stains black (dead algae). The pollution of the world gets carried into the atmosphere and falls down even on MB with the rain and snow deposits. Wipe the astrigal or brush stripping on the bottom of those casements with a white cotton rag and I'm betting you'll find a black streak on it too.

That's my (s)WAG.

Areas that don't dry immediately due to drainage plane (screened window units retaining water on sills) and the sun-not-shine-on-intensely zones.

Regards to exterior to the envelope chimney chase, infiltration at the roof framing, inproper flashing, sealing, drainage, attic superstructure retaining moisture.

Everyone, thank you for your input.

No kick out flashings present and I'm certain copious amounts of water pour over the gutter during heavy rainfalls. Also, the seals around the windows are also highly suspect. Water has very likely caused damage to this home but what I'm trying to find out is if the black stains are a definite sign that severe damage has already occurred (i.e. enough to break the tar paper or wood down into minuscule black particles that end up staining the exterior). Or, is it also possible that the stains have nothing to do with damage?

So it may be rotting building materials or it may be dead algae. A dilemma I suppose since I'm sure there aren't any certified stucco inspectors in Winnipeg. Is there any on site testing that can be done to determine if the stain is rot or dead algae?

Thanks again.

Originally Posted by Ian Currie

So it may be rotting building materials or it may be dead algae. A dilemma I suppose since I'm sure there aren't any certified stucco inspectors in Winnipeg. Is there any on site testing that can be done to determine if the stain is rot or dead algae?

Carful..... you're starting to tread in dangerous waters.... It's not your problem that there aren't qualified people to check out stucco/EIFS. Don't let that lack of people to check it out make you take on more liability or try to do more.

The absolute last thing you want to do it lead someone to believe you are doing more than you are able/qualified to do. The fact that you're asking about what to do makes me think you're in over your head and should stop.

Originally Posted by Ian Currie

Everyone, thank you for your input.

No kick out flashings present and I'm certain copious amounts of water pour over the gutter during heavy rainfalls. Also, the seals around the windows are also highly suspect. Water has very likely caused damage to this home but what I'm trying to find out is if the black stains are a definite sign that severe damage has already occurred (i.e. enough to break the tar paper or wood down into minuscule black particles that end up staining the exterior). Or, is it also possible that the stains have nothing to do with damage?

So it may be rotting building materials or it may be dead algae. A dilemma I suppose since I'm sure there aren't any certified stucco inspectors in Winnipeg. Is there any on site testing that can be done to determine if the stain is rot or dead algae?

Thanks again.

Hey, I can make it up there with no problem. I can get a direct flight on Air Canada out of Nashville! My fee would be airfare, lodging and time on site. I would estimate to be around $1,500(US) for the inspection. Let me know and I can make it sometime next week!

Ian, if there is any indication of moisture in the walls, you could recommend someone do an IR scan of the interior walls in those areas. Surely there are inspectors with IR cameras in Winterpeg?

Also, small holes can be cut and a boroscope can be used to check inside those walls.

Has anyone checked the drywall under the windows with a moisture meter? Maybe after some heavy rain or with someone spraying water against the wall. My first impression is that those are algae stains as mentioned. Soap and a brush should take most of it off. But the caulking is kaka, from the look of it.

The area under the eaves by the chimney needs a closer look, because that is not a normal condition. Ladder and a moisture meter, for starters.

Were you able to determine what type of stucco?

Matt,

I heed your warning. I realize that we are generalists, not specialists and that our inspections are limited. I state that in my contract and limitations wording and I highlight that fact when I sit down with the client prior to the inspection.

I've already recommended that the client hire a stucco contractor that specializes in repairs (for their expert opinion) or a thermographer (to determine if there is moisture under the stucco).

I'm just curious to know if there is any 'simple' way to determine if it is rot vs. benign staining, but it sounds like there isn't (unless I can get Scott up here!).

John,

Just saw your post now.

There was a damaged portion on another exterior wall that I was able to peek under. It's definitely stucco and not EIFS, if that's what your asking.

And yes, there are a few people with IR cameras here - but the selection is limited, and most of them are electrical contractors who use them strictly for electrical applications.

All your pics are of walls on the shady side of the house, does the same stain show up on sunny walls? If not, I would look at surface mold stains first. May have nothing to do w/stucco.

I can not tell if the top left gutter is cut to allow the water to drain. No matter what else is occurring I agree with the suspicion of the guttering system. There is a problem at the chimney with the water not getting into the gutter where they probably tried to caulk the gutter to the chimney instead of flashing. Yea, get a stucco expert. I hear there is one in Nashville.

Originally Posted by John Carroll

All your pics are of walls on the shady side of the house, does the same stain show up on sunny walls? If not, I would look at surface mold stains first. May have nothing to do w/stucco.

All of the sunny walls are limestone from foundation to roof and show no signs of staining. The opposite side of the chimney chase is stained too and faces the sun. Admittedly the staining isn't as pronounced.

Originally Posted by Ian Currie

All of the sunny walls are limestone from foundation to roof and show no signs of staining. The opposite side of the chimney chase is stained too and faces the sun. Admittedly the staining isn't as pronounced.

Mr. Currie: If the walls are on the shaded side of the house and the cladding is indeed Portland cement stucco, then Mr. Carroll is leading you down the right path.

As a generalist it is your job to note any missing flashings, expansion joints, failed sealants, et al. It is then your responsibility to defer to an expert. That would not be a stucco contractor or a thermographer. That would be a stucco inspector, such as Mr. Patterson or Mr. Turestsky, or Mr. A.D. Miller.

Someone may have already said this but I recommend you go to the Exterior Design Institute web site and look for someone close to you if possible. Someone said $1500 plus out of pocket and I think that is correct.

My look at the photo's makes me think that this is a conventional stucco home. The lack of sealent around the windows usually says it is not EIFS. Now it can be but if thats the case then it is installed wrong. All the other comments are good and the post Steve T from NYC about kickouts is somewhere to start on this problem. You need moisture tests along with substrate evaluations. It's not a big deal to do however not all have the meters required and the knowledge and training. Some do however call Branda At EDI Exterior Design Institute - Contact Us

Well said brother William.

Elliot, Mr Brady belongs on that shortlist.

Originally Posted by William Brady

call Branda At EDI Exterior Design Institute - Contact Us

I'll do just that, call Brenda that is. I'll be honest, it never crossed my mind to recommend flying a stucco inspector in to have a look. We have local experts for any other system that might need an expert's opinion so I've never had to recommend someone from out of province.

Recommending an expert is definitely the best thing for my clients.

So, if any stucco inspectors want to provide me with contact info, inspection pricing and anticipated out of pocket expenses send me an email so I can add to whatever list Brenda starts me off with.

Regardless, it appears that the general consensus is that the stains are algae growth since they're on the shaded side of the home (except for, perhaps, the brown stain on the chimney chase, which may be a sign that further inspection / testing is required). With this thought in mind, is it anyone's opinion that a stucco inspection is needed if a home has black stains on only the shaded side of the home (like the ones in the photos - let's pretend, in this case, that the brown stain on the chimney chase doesn't exist)?

I'm curious to know since in the future I wouldn't want to recommend a stucco inspection if the symptoms simply don't warrant one. As an analogy, it would be wrong for a home inspector to blindly recommend a foundation specialist every time he merely finds a crack.

Here's the link to the web site that sparked my question in the first place; tjllc (see the middle column). Any comments about the info contained in this web page?

Here's an interesting read that has some frightening statistics.

Woodbury Minnesota Stucco Questions and Answers

It looks like every stucco home built using 'traditional' methods- will need a stucco inspection once the age of 8 years is reached.

Ian, did you put your ladder to what I see is the worst spot on the house, the chimney. If you look closely at it you see there is a dry spot between the wet spots. Water is dumping from around the chimney (is there a saddle?) and not getting into the gutter and surface tension is throwing it against the wall. Get up there, tap it with a screw driver handle, wet spots and dry spots. Listen for a change in sound, a change in consistency. Smell it. I can hear the laughing from the gang of experts, but what I am saying is that we have more senses than sight and when it comes to whats behind the wall we can do a couple of things. Call in the electronics and measuring meters and the people smart enough to run them and pay them big bucks out of your clients pocket, or deduce what is causing the problem. I can not tell what size the gutters are but they need to be 6" with 3x4 downspouts and flashed so the water gets into the gutter. I guess what I am getting at is if the client follows your advice and gets in all the experts on stucco and they say, yeah, you got excessive moisture in that wall. So they end up tearing out the stained areas, re plastering, painting, and everything is fine except the water is getting to the new just as it got to the old. Are the window sills finger jointed wood? A little over ten years seems to be what they last.

Originally Posted by Ian Currie

Here's an interesting read that has some frightening statistics.

Woodbury Minnesota Stucco Questions and Answers

It looks like every stucco home built using 'traditional' methods- will need a stucco inspection once the age of 8 years is reached.

Mr. Currie: From that article:

Window leaks, a lack of kickout flashing, improper deck flashing, and grade above the wood framing are the primary causes that account for the majority of the damage. All other causes are secondary. Generally, walls without windows or other openings sustained little or no damage. Unfortunately, even after five years of conducting thorough investigations there remains many "mystery areas" where the cause of damage is unknown.

Bear in mind that the issues listed stem from poor installation practices and not any sort of inherent defect with Portland cement stucco. The statement in red indicates that the persons inspecting the houses (municipal employees) are not any better at identifying problems during forensic inspections than they are in preventing them during phase construction inspections.

But then, we knew that.

Originally Posted by Ian Currie

I'll do just that, call Brenda that is. I'll be honest, it never crossed my mind to recommend flying a stucco inspector in to have a look. We have local experts for any other system that might need an expert's opinion so I've never had to recommend someone from out of province.

Recommending an expert is definitely the best thing for my clients.

So, if any stucco inspectors want to provide me with contact info, inspection pricing and anticipated out of pocket expenses send me an email so I can add to whatever list Brenda starts me off with.

It is done all the time and not just for Stucco. I was just involved with a large home and I was part of a team of inspectors. One guy who specializes in round type fireplaces was brought in from New Mexico. Me, I had to drive about an hour!

Tell your client that they will also need to rent a boom lift for the inspector to do a proper job. It is kind of difficult to travel with those 30' ladders!

Good day Mr. Franson,

I agree with you wholeheartedly.

For many years I have stated that the worst enemy of any house is water (moisture), regardless of the cladding. Whether it is from a leaking basement, leaking roof… or anything in between. Lets us not forget that in addition to intruding water, houses that are lived in create their own internal moisture.

The only saving grace that a house has is its ability to dry out, which translates to permeability and air exchange. In today’s world, with increased insulating practices, vapor barriers, moisture barriers, and more efficient windows, houses leak less… breath less.

Regarding sand mix stucco, I have stated elsewhere in this forum that sand stucco shows many of the same faults as EIFS, and it does. For those that will argue that sand stucco dries out, yes it does. But what about the water (moisture) that has intruded behind the moisture barrier? Or, double moisture barrier if applied properly? (A single moisture barrier affords no internal drainage plane.) Where does the water go?

As far as older stucco, keep in mind that many older homes have no insulation, and leaking windows, so even if they couldn’t dry out, they were able to dry in.. Besides, for those that have never gutted older stucco homes, there are plenty with damage.

Regarding ALL other claddings, flashing and drainage is always important. Lets not forget weep holes and a drainage plane in brick veneer.

Phillip,

I don’t think anyone is laughing. I simply believe that anyone that is familiar with building envelope inspecting and moisture analysis believes that all building envelopes should be inspected. There are no ifs, ands, or buts. This is usually done during a normal Home Inspection, or should be anyway. In homes with permeability and/or air exchange that has been retarded, the inspection must go a bit further. Testing beneath the surface must be done to determine the effects of the anomalies.

Ian,

If truly there is no moisture analyst in the nation of Canada, perhaps you should begin the process of learning. You could become a national hero. You may end up becoming a future Prime Minister.

Originally Posted by Ian Currie

Here's an interesting read that has some frightening statistics.

Woodbury Minnesota Stucco Questions and Answers

It looks like every stucco home built using 'traditional' methods- will need a stucco inspection once the age of 8 years is reached.

Mr. Currie, it appears that you have been doing your homework. Woodbury, MN is 5 miles away from me - so thanks to their data, stucco moisture testing is very common here. We're pretty good at it. The data is still coming in, stucco issues continue, and it's stunning.

Well, I spoke to Brenda today. She's confirmed that there is a grand total of one (yes one) certified stucco inspector in all of Canada. He hails from somewhere in Ontario. She also told me that she's not even certain that he's still performing these inspections - she's called him in the past without a response.

There may just be room for some competition - but I have to ask the question; why is no one else doing this? There is obviously a need, but if homeowners don't know that there's a need and the government doesn't mandate stucco inspections to be completed by a certified inspector, then there may be no clients either.

I'll probably take the course anyway, just so I know what I'm doing.

So,

Any suggestions as to which course is best to take for my needs?

EDI, InterNACHI, any others?

Thanks.

Originally Posted by Ian Currie

So,

Any suggestions as to which course is best to take for my needs?

EDI, InterNACHI, any others?

Thanks.

EDI hands down! After you take the EDI course I would also look into taking the course offered by AWCI as well. While they are similar the AWCI course is slanted toward the manufacturer and EDI is not. I took them both and learned from both. Northwest Wall and Ceiling Bureau is another one to look at.

I agree with Scott. EDI without hesitataion. I enjoyed EDI's advanced class because it was geared more to inspecting and not towards installing, as Scott pointed out.

There are other classes too. The more you learn the better. Actually, there is a specialty class coming up in two weeks in Chicago.

In between classes, get as much practice as possible. Test as much as you can. Build up some history so you will have a foundation to draw on. You will learn ... when you see this, it means that. Many of you conclusions are based upon experience with similar conditions that you have encountered at other sites.

don't hesitate to make some calls to EDI inspectors around the country. Sorry it may be only the USA you are dealing with. Make those calls and talk to EDI inspectors. You will leard what they charge and how the cost are arrived at. Travel for them in a case like yours will be what the out of pocket is, along with maybe an overnight. You can call me anytime and I will guide through the process. I am not looking for the work necessarly all I am interested in is making sure you are getting the best info. As to training I can also tell you about EDI and my experience with that organization. So the rest is up to you. Good Luck.

Originally Posted by jannypan

I guess this is EFIS as I don't see any control joints?

Many stucco homes do not have the required control joints - I would not use that as a basis of determining EIFS or stucco.

In some cases building enclosure consultants were proven to do more harm than good, by their errors and omissions, as well as by the way they are incentivized. They typically partake in risk but not in expenses; therefore, they may often suggest more expensive materials and systems than necessary to assure a facade’s functionality.

going by the pictures most of the stains appear to be dirt etc run off of the windows and gutters.
the chimney though appears to be a water penatration problem, especially if it is stucco over masonary, that is hard to tell without control joints near the building.

Originally Posted by Ian Currie

Hi,

I've come across a 13 yr old home with black stains on the stucco originating from the bottom corners of vinyl windows and where the eavestrough meets the wall and chimney chase. There are also other stains (dark brown) along the chimney chase (see attached photos).

I've read articles that say these types of stains are from broken down tar paper or wood particles (caused by years of water penetration) but I've also read other articles that claim such stains can simply be from airborne contamination (I have doubts that this is simply staining from dirt or pollen).

Does anyone know the most likely cause of these stains?

Thanks.