Thread: Best Fix Recommendations for Stucco Problem?

Hey Everyone,

Not a home inspector here, but relying on your experience for the best fix for my problem please. We have a 3.5 year old 2 story home in Ocala, Florida (North Central Florida). The metal lath is rusting through the stucco finish and has actually bubbled/buckled through in a spot. We are getting estimates on getting the problem areas fixed, and then to paint the entire house again. This is a Pulte built home, block on the bottom, OSB and wrap on top, with metal lath and a single coat stucco over the entire house. There are several issues that may have led to this outcome (stucco not cured properly, light stucco coat, inferior paint/number of coats, weep screed installed backward, weep screed holes mostly plugged, etc.) My questions/concerns:

• What is the best way to hopefully make sure this doesn't rust through in other areas? Seal the entire upper area first, and if so what type? What type of paint for a top coat? Each painter that has come out has recommended a different type, but the majority are using some type of elastomeric, with 2 coats over the sealer.
• I feel like I need to get a "stucco expert" to determine what is actually going on here so I can fix the cause of the problem so this doesn't continue. Or will re-opening the weep holes and a good paint job solve the problem?

I apoligize if I left critical details out...I tried to include what I found on the boards. Pictures attached are the larger bubbled/buckled area, approx. 1' high x 6' wide. The rusted area is the left end and it extends to the right, although it is difficult to see the contrast on the pic. The other pic is a close up of the rusted area. Thanks in advance for your thoughts...

Jason

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Originally Posted by Jason Ramey

...I feel like I need to get a "stucco expert" to determine what is actually going on here ..

Bingo.

Originally Posted by John Arnold

Bingo.

What John said.

Originally Posted by A.D. Miller

Stucco does not have weep holes.

Sorry, was referring to the weep screed holes. The vast majority are plugged with either stucco or paint. Just wondering if this along with a good paint job will do the trick.

Originally Posted by Nick Ostrowski

What John said.

Is there a particular certification or license I should be looking for? I have had several plastering contractors out and have had just as many reasons identified as the cause. I'm sure they all would identify themselves as "experts". And the stucco guys say it's a bad paint job and the painters say it is a bad stucco job. That is after they take a poke at their competitors that did the original work of course...

Originally Posted by A.D. Miller

Weep screed, per se, is manufactured with and without holes punched in the protruding lip below the vertical attachment flange. I do not believe that holes punched in the angular protrusion are necessary to achieve good venting at the base of the wall.

Find a contractor who is a member of a major organization like (in your case) nocsa.org , awci.org , et al. If the contractor is using a particular manufacturer's system, ask him if he carries certification from that manufacturer for the installation of that system. Additionally, ask for proof of insurance, any locally-required licenses, BBB reports, Angie's List ratings, etc.

Thank you for the info, very helpful.

maybe a good coat of KILLZ will seal it and buy you a few years ?

Go down to The Home Depot parking lot. You'll probably find the guy who originally put it on. That's likely what Pulte did.

Originally Posted by james hise

maybe a good coat of KILLZ will seal it and buy you a few years ?

KILLZ will only temporarily mask the problem while it persists and gets worse.

Unfortunately it looks as though the brown coat is installed improperly (appears to be a one coat system)you should not be able to read the lath pattern through the finish. Water intrusion has caused the lath to rust, this will continue regardless of what type of coating you install on top of your existing stucco. The affected areas should be removed and replaced as stated earlier in this thread. The use of a perforated screed does help drainage along with a flashing fastened under the first layer of felt paper(make sure there are TWO layers) should also be installed to divert any water that gets behind the first moisture barrier. My guess is that a one coat system was used as they typically are the fastest and cheapest way to get the home finished, sadly not the best. Some of the manufacturers use one coat with fiber additives and a synthetic finish, if you must this, is a better way than what you have. Again as said above get a reputable contractor and get it done right. Any recourse with the builder, warranty possibilities? I’m leaving town for a week be glad to answer any questions you might have when I get back.
Best of luck,

I have not read the entire thread but I would recommend that you go to this site for a stucco inspector in your area

www.exteriordesigninstitute.org.

Originally Posted by William Brady

I have not read the entire thread but I would recommend that you go to this site for a stucco inspector in your area

www.exteriordesigninstitute.org.

Your link no worky. You mean this place?

Exterior Design Institute - The absolute best in EIFS Inspector training.

Sorry thats the one. Just click on inspectors and your state and look for one in you general area. Good Luck.

Hey Bill, I hope all is well in N.M., S.I. is... well, your not missing much.

Jason, Without being there I am hesitant to suggest a fix, but it sounds like you have a mess. Is it only rusting where the stucco is installed over wood? I wonder if the wood below is rotting out. I suggest an inspector check the moisture content of the wood sheathing. Like Bill says, contact EDI. See who they have in your area.

Hi Jason,
Our company specialises in exterior system repair solutions such as this. Although we're located down here in New Zealand, I believe the cause and repair will apply equally in Florida.

As one of the members mentioned, the most likely cause is water ingress through or behind the plaster. This may be from cracks or from an overflowing gutter from the short eave above. Look for any sources of water ingress first. Is it sealed to the eave?..is the construction join properly done?...

If theres no apparent faults and if this rusting is not a generic fault to the whole house, then its likely to be a sheet of lath that either hasnt been properly galvanised at the factory or has been damaged on site to the point where the coating was scoured and rusting started before installation.

Either way, putting more paint on top isnt the answer, as the rust will exert tons of pressure to blow it off eventually. It wouldnt be economic or good practise to try and rustproof it if its got to this stage, as youd have to get in and around the lathe wire or perforations and it would just be impractical. Best to replace this sheet and any affected, and replaster, ensuring that the vapour barrier isnt damaged in the process.

The paint appears to have pin holes in it, this won't be helping. A good elastomeric paint coating is recommended, provided the souce of the problem is sorted out firstly.

Hope this helps,

Cheers
Keith

Hi ALL &

Yessirree - 'Replace' (at least partially, as needed, since those photos don't show the complete exterior) is the answer !

Try to think of that entire face-sealed stucco exterior as a 'raincoat' & thus it needs to be "1-piece" & reliable to shed water (never mind 'looks').

Trying to put myself in your shoes, so to speak & I'd also try to find out who actually did that mess in the first place for Pulte & make sure to stay-clear...

Any warranty coverage at all ?

Good Luck with that project.


CHEERS

I'm familar with Pulte stucco issues in SC. I'd recommend an IR thermography survey outside and inside, follow up problem areas with moisture meter. Most likely water intrusion from flashing or improperly installed mesh/damaged to drainage plan. Check with Pulte on stucco warranty. In SC we have 10 years.

Keith - A.D.'s nastiness is his own form of entertainment. No doubt you've run into his type before.

Welcome to Inspection News!

Hello Steve,

All is well and I keep up with things back home. Hot here now really hot don't know how to say it. It's hot. Hope all is well with you and the stucco business is going strong. Maybe EDI will be having something this year and we can run into each other.

Jason,

Is the bathroom shower directly interior to that stain?

Originally Posted by A.D. Miller

Kiwi Boy:

Painting stucco is a stupid idea no matter which side of the equator one is located on. As a "specialist", you really should already be aware of this. Perhaps the word has a different meaning down under.

Texas Boy,
Thanks for your comments .. I'm grateful to be enlightened by one who may be wiser, but actually stucco, if youre talking 20mm on lath, MUST be painted or coated with a penetrative sealer to keep out moisture which leads to this lath rusting. There wouldnt be one stucco house down here that isnt painted, and if you look at the advice on US house forums, most everyone recommends painting. (AskTheBuilder.com/ Google Answers... Here we go, heres a good ol' boy architect in Houston :....

"I'm an Architect in Houston. You should use an elastomeric paint. Weuse this on new stucco as well. It stretches to hide any hairlinecracks that form. It also keeps moisture out."
Maybe it doesnt rain as much in Texas, but hey, just trying to help the guy.

Hi John , thanks very much for your welcome, mate. Thats really how they entertain themselves in TX?..huh!

My forte is horizontal surfaces that shed water; and on some of my rehab jobs I've found expanded metal lath that had rusted out even with/despite cementious deck coating/waterproofing troweled into it.

In these cases we found that the lath was electro galvanized, not hot dipped as required. In locations adjacent to salt air (California coast, or Florida), the rain picks up a lot of salt laden moisture and drives it into stucco from the wind.

Ten bucks says the Pulte sub came in with cheap lath instead of hot dipped lath. Lath is currently $7.00 per sheet for Hot dipped, $4.50 for electro here in Cali. On production housing, that can save the sub thousands of dollars...

I'm doing a deck over now that had electroplated lath, it's all rusted and now it's all coming off. Water seeped in over the last 6-7 years since the house was built and the deck failed prematurely.

The lath will have to be removed and replaced...

Jason,
There are great bits of information stated on this thread, here in the beautiful garden state, we deal with winter and hot humid summers, I am very fortunate to have been a transition engineer inspector in the multi family industry and have observed and documented many square miles of this materials ripped off and observed it going on. About a year and a half ago, I teamed up with one of the largest non union stucco contractors here and started to compare notes...this comment is based on just that, it may not apply in Florida or it may be one cure of many needed for this product nation wide or stucco can become a thing of the past and EIFS is the best product, I dont have a opinion to that just yet.

Although not recomended, if you have isolated damage, I can email you photos of how we perform repairs and lap into existing systems.Dont like doing it, but owners and developers dont budge the other way because of $ and the attitude its not broken over there (YET) so we dont have to fix it.

Theres information needed on your home through invasive cutting, one gentleman mentioned the grade of mesh,or rain water could of blown in and washed some brown coat off during application, maybe they didnt fasten the mesh into the studs. I have seen it all and there never seems to be just one problem contributing, but 2 or 3. Example...a gable truss bottom chord not nailed on the top plate correctly, expands, moves and rips apart a control joint, or theres capillary effects from a jacuzzi on outside wall with no dry wall installed on the outside wall beneath the tub lip and from no insulation behind a simple electrical outlet with a plywood seam behind the outlet box...all crazy forms of failure. Speaking from jersey prices do I spend many hours arguing with developers $28 per square to rip it all off or $40+ to surgically remove and tie into old.You will need good invasives and reputable contractor pricing help decide and repair.

Another problem noted, it appears your photo shows stucco right up into the window with no casing bead and caulk joint and at the window heads theres no drip cap and weep screed. The one photo I enclosed shows hard coat with a foam detail in motion of repair. With this style window, we first friction fit AZEK into the intergrated channel around the windows perimeter, this gives a better surface to permit adhesion for the soft joint application. The windows head is drip capped and weep open for moisture.

The only building wrap I have not seen fail is weather trek, this paper has a unique pattern that creates airspace to reduce solar driven inward moisture drive.The photo with the with fungi is behind Tyvek, this southern facing wall thermal imaged at 137 degrees at noon time a month ago during invasives and was just completly removed last week, all capillary failure. Moving forward, they are installing two layers of weather trek,proper drip cap and weep screed, self furring lath, 3/4 "thick minimum coat applications, plastic control joint not stapled but tied like metals specified, self ahered flashing behind wall componants like at the foundation framing break, around windows, behind control joints, around pipe penetrations, every where behind the drainage plain where componants are installed. If you want email me at ewooddogs@aol.com, I will send you the standards C1063 and C 926 and pictures of the stated applications in motion if you want, you can let your stucco consultant review them, they may agree or disagree with me but its working here in NJ. In case you pursue legal action, the standards are red highlighted on the changes, so you will need to see what code was adopted at the time your home was constructed, then order the years copy for about $40 from ASTM, for instance, they may have used 1 layer of paper and were really over the cusp when 2 was required.

This material needs to be protected during installation just like a horizontal floor slab from wind and sun. I know contractors dont bid it this way, but a blue tarp wind and sun screen secured over the pipe scaffold during curing goes a long way to limit cracking, takes an hour to set up...sounds like the only diference between Pultie in Florida and New Jersey is a 1000 miles.

Heres some good diverse reading on OSB sheathing, gives you an insight to the how this material is in reaction,

Technical bulletin "OSB and the Humid Enviroment" from Structural Board Association

Insight Stucco woes, the perfect storm by Joseph Lstiburek from Building Science Corporation

and search for "Moisture Exchange" Performance of OSB and Plywood Structural Panels, by Lonnie Haughton and Collin Murphy

Attachment 18122

Attachment 18123

With all the goings on regarding the stucco/lath/drainage plane, I wounder what the condition of the wood substrate beneath the stucco is like? The rust is an indication of something that is wrong, and if all is well except for defective mesh, it is one thing. Is the symptom wide spread? Is it only occuring where the substrate is wood, or on top of the masonry substrate also? I am curious what the moisture content of the wooden substrate is... if it still exists. I say probe testing is in order.

Originally Posted by A.D. Miller

Kiwi Boy:

From the attached pdf:

Stucco Substrates

Ideally, in cold climates, stucco claddings/renderings should not be
topcoated with paints. Color pigments should be integrated into the
topcoat/finish layer of the stucco itself. Unfortunately, this practice is
no longer common, and stucco now is typically painted.

When painting stucco, water repellant vapor permeable coating paint
systems are recommended. Recall that water vapor flow occurs from
both a higher concentration to a lower concentration and from the
warm side of an assembly to the cold side of an assembly. A rain wetted
stucco cladding that is heated by solar radiation will be warmer and
wetter than both the interior and the exterior air. Drying will be to the
outside and to the inside. A heavy coat of impermeable paint over exterior stucco will blister under such conditions. The more vapor permesureable the exterior paint coating, the better under such circumstances.

Acrylic latex paints formulated for exterior use are recommended for
almost all stucco applications.

Acrylic latex paints generally outperform "elastomeric" paints over
stucco renderings due to the lower permeability of the elastomeric
paints. Elastomeric paints have excellent crack spanning characteristics,
but give up a degree of permeability to achieve the crack spanning
ability. If water enters the stucco rendering at a joint or reveal or flashing
or flaw, elastomeric paints have been known to blister. Elastomeric
paints should be reserved for special conditions where substrates are
severely cracked and crack spanning coatings are necessary and no
other coating approaches are practical.

It is important that the stucco has cured sufficiently to reduce its pH*
prior to painting neutral pH (not acidic, not basic, just right — the
"Goldilocks" pH is 7) is ideal for paint application. To determine the
pH of stucco prior to painting, use "litmus paper" or just wait — 28
days is often recommended.

If waiting is not practical, apply a masonry primer containing alkali
prior to painting.

Thanks AD for the post.
youre right in that impermeable paints will blister if there's moisture behind them. Most good elastomerics are permeable though, to allow sufficient transpiration of moisture, but certainly not rivers of water.If stucco isnt sealed then it remains porous and mositure just has to get in, unless there is water barrier impregnation mixed in. I can't agree with the article when it says the colour should be mixed in. We've seen too many cases done like this where the plaster will bloom or effloresce due to no top coat sealer

In my humble opinion then, I'd say to look for the source of the problem(presuming its not bad lath). As Ken Rowe mentioned, it could be a leaking shower on the inside.Or indeed an overflowing gutter or leaks from failing flashings to the window.

Down here in NZ, we've a huge problem similar to Canada and California with leaky plaster houses, and the problem has been mainly architectural monstrosities with bad flashing details.Sand and cement stucco is one of the worst culprits here and is replaced mostly now with acrylic systems using fibreglass mesh.

Cheers

KiwiKeith

Originally Posted by A.D. Miller

Kiwi Boy:

As you wish. The author is Joseph Lstiburek, Ph.D., P.Eng., ASHRAE Fellow . I have attended several of his lectures, read several of his books, and seriously doubt that you would stand a snowball's chance in North Central Texas in mid-August of successfully arguing your case with him, or me for that matter . . .

Cheers, There's no flies on you, AD . Actually I'd welcome the chance to sucessfully prove my case. Its simply from practical experience over thousands of houses repaired .Last time I was in Dallas, I noted the differences in detailing flashings to EIFS and stucco houses to what we have here.Its interesting. Sometimes snowballs do stand a chance...

Originally Posted by A.D. Miller

Kiwi Boy: The flashing details in this area are, for the most part, either wrong or missing altogether. The last time I was in Aukland was in another lifetime . . . As for the snowballs, this is only June and the temperature is hovering around 100° F. August is truly a bitch . . .

Thanks for the comments AD. For the record, The paint thing: its a known stucco fault down here,(having impregnated colour) and we have brochures describing it and some others on flashing systems we've developed here. If youre interested Im happy to email you copies.I really was in Texas some years back, really enjoyed it, and plan on being there again in several months.
have a good one....

KiwiKeith

A professional exterior cladding specialist performed tests on the impermeability of stucco by itself, and the results were if stucco is properly applied it does not have to be painted to be waterproof. I think there are a couple of issues going on with that home. Improper stucco coverage of the lath, paint was sprayed on in the beginning and never back rolled leaving lots of little pinholes in the already too thin stucco. In addition there is no casing beads on the windows and I question how the disimilar unions of the stucco to windows, expansion joints are sealed.

Eric Fogle
Reassurance Services Inc.
Central Florida

Originally Posted by Jason Ramey

The metal lath is rusting through the stucco finish and has actually bubbled/buckled through in a spot. We are getting estimates on getting the problem areas fixed, and then to paint the entire house again. This is a Pulte built home, block on the bottom, OSB and wrap on top, with metal lath and a single coat stucco over the entire house. There are several issues that may have led to this outcome (stucco not cured properly, light stucco coat, inferior paint/number of coats, weep screed installed backward, weep screed holes mostly plugged, etc.) My questions/concerns:

• What is the best way to hopefully make sure this doesn't rust through in other areas?

Okay, you did ask "What is the best way ... ". The ONLY WAY " ... to make sure this doesn't rust through in other areas" is to removed the stucco down to the house wrap, probably replace the house wrap or at least put another wrap over the now damage wrap, then properly install paper backed metal lath, properly install the correct stucco accessories (weep screed, etc.), then properly stucco the house as it should have been to start with.

If you are asking for something less then you will need to set aside the idea of " ... to make sure this doesn't rust through in other areas" as you will need to accept that it will continue to happen until the stucco has been all removed and installed (the wrap, paper backed metal lath are "installed", the stucco is "applied") correctly.

Yes, I realize that is an old post, but that is the only way to solve the problem.

Go back and look closer at the rust spot picture. See the holes, holes that you believe are in the paint? I've got bad news for you, those are holes in the stucco, caused most likely from air entrainment in the mixing process. Probably mixed in a bucket with a paint mixer paddle. This type of paddle puts tiny air bubbles in the plaster mix and when they evaporate, only air is left where there should be plaster. You are living in a colander, sir, and unfortunately, JP is right, it all should be removed and done properly.