FAQs about stucco wall covering method choices, methods, & comparisons.

This article series discusses types of stucco building exterior wall materials and installation methods, including stucco recipes, three-coat stucco installations, stucco wall expansion joints, metal-lath stucco systems, how stucco is applied to walls, thin coat stucco systems, EIFS synthetic stucco wall systems, and the role of weather and moisture in stucco wall installation, durability, and painting success.

Q&A on Stucco Product Choices & Installation Methods

These questions and answers about the methods of stucco wall installation, troubleshooting repair methods were posted originally at STUCCO WALL METHODS & INSTALLATION - be sure to review that article.

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On 2018-03-26 by (mod) - Sheathing under wire lath for stucco

Alan:

Typically sheathing under wire lath is 1/2" CDX on modern wood framed structures.

Michael:

I wish I could help but I can't hazard a guess at what your neighbor used in his stucco mix nor in applications of any sealant. But perhaps I'm confused by the wording of your question.

It is the case that improper stucco application AND/OR premature application of a top coating of paint or seralant before stucco has dried fully can result in a white bloom problem.

See

• EIFS FAILURES vs WORKMANSHIP
• EIFS STUCCO SEALANT APPLICATION

On 2018-03-26 by Alan R.

What is the best sheathing material AND thickness to use under the wire lathe? If it matters by climate, I live in the Dallas, TX area.

On 2018-02-28 6 by Michael Zwick

I recently had someone stucco my backyard wall's. They are shared wall's by neighbor's. He was suppose to put a sealant on first and then a one coat coverage , floated on . After he was finished I water sprayed with hose a couple days after the wall's

It dried and I waited a week and few days . I noticed that there were quite a few areas that remained wet. We haven't had rain the whole time.

I want to know if he put water sealant on the wall's because these spots are still showing wet and not drying. I want to have a painter to paint the walls but they are still wet in these same area's.

On 2017-09-05 by Zizi

I got my wall and house stuccoed last year. My stucco contractor used non galvanized cement nails to attach corner aids to my exterior wall. He said he needed to because he was applying the aids to the existing stucco underneath, and only non galvanized nails are strong enough to do this.

After one big rain, all the nail heads began to bleed through the finish coat and paint. I counted 91 rust bleeds so far. My question is : Should he have used non galvanized nails, or sonething else? Thx.

On 2017-05-03 by (mod) - instructions for installing Sto Powerflex Fine

Ervine, if you are asking about 80280 Sto Powerflex Fine, Sto describes the product application using trowel or spray. So not try a roller. Here's a quote

Apply only to sound, clean, dry, properly prepared, frost-free surfaces.

Trowel Apply Sto Powerflex with a clean stainless steel trowel to a rough thickness slightly more than the largest aggregate size. Use the trowel to scrape the material down to a uniform thickness no greater than the largest aggregate size.

Achieve final texture by floating with the appropriate trowel in a figure eight motion with a plastic float.

For Sto Powerflex Freeform, application thickness varies depending on the pattern or texture desired. Apply to a minimum 1/16" (1.6 mm), maximum 3/16” (4.8 mm) thickness in one pass.

Texturing may be achieved by trowel, special roller or putty knife.

Once applied, the working time is up to 20 minutes depending upon material, ambient temperatures and surface conditions. Spray Apply Sto Powerflex with a hand-held gravityfeed hopper type sprayer, texture spray pump machine, or other appropriate equipment such as the StoSilo system or Sto’s M-8 spray pump.

Apply an even coat to ensure full coverage of the surface. (Spray application is not recommended for Sto Powerflex Swirl). IMPORTANT: ALWAYS check color for proper match. If color does not match, STOP–call your Sto representative.

For best results always prime cementitious substrates. Apply coating in a continuous application, always working from a wet edge or architectural break to eliminate cold joints. Minor shade variations may occur from batch to batch (refer to batch no. on pail).

Avoid installing separate batches side-by-side and avoid application in direct sunlight.

Avoid installing new finish adjacent to weathered or aged finish.

Sto Corp. will not be responsible for shade or color variation from batch to batch, variation caused by application or substrate deficiencies, or fading resulting from natural causes such as weather.

See Tech Hotline Nos. 0694-C, 0893-EC and 1202-CF for helpful tips on prevention of color problems. Protect installed product from rain, freezing, and continuous high humidity until completely dry.

That was from
Product Bulletin
Sto Powerflex®
80280 Sto Powerflex Fine
80281 Sto Powerflex Medium
80282 Sto Powerflex Swirl
80283 Sto Powerflex Freeform

On 2017-05-03 by Ervine

Can you use a paint roller to apply sto fine and base acrylic stucco to a scratch coat parging then spray a texture on it

On 2017-04-22 by (mod) -

If it were my house and I had the money I'd do a tear off.

And maybe post some plastic owls at the corners.

On 2017-04-22 by Chris p

It is a big job, but the damage is year after year on all sides of a 6000sq home. I am also not sure of past damage that has been repaired that could potentially be a problem. I agree with your comments and question the process. I will post the on the other site. Thank you

On 2017-04-21 by (mod) -

Chris:

Sorry to be obtuse but are you really proposing to tear off ALL of the existing EIFS and go to traditional stucco? That's a really big expense to deal with woodpecker damage.

I would add that if you want to leave the old EIFS in place

- you will have to build-out the trim around every window & door, receptacle, light fixture, etc.

- if the new layer of exterior material isn't perfectly-sealed and leaks water will be trapped into or behind the EIFS inviting rot, mold, insects

- having multiple layers of stucco without a drainage plane behind the newest layer is inviting a building moisture or water trap disaster

At the top of our page you'll see a link to our little sister Steve Bliss BuildingAdvisor.com - hop over to Steve and post your question there to see what Steve thinks. I bet he'll be as worried as I am.

On 2017-04-21 by Chris p

Dan,
Sorry I should have explained more....i want to replace the EIFS with true stucco and it was stated that I don't need to rip off the EXISTING EIFS, but place lath over the top with screws penetrating the OSB and coat with new stucco

On 2017-04-21 by (mod) -

Is the question about repairing holes or about asking the woodpeckers to peck elsewhere?

The proper repair depends on the specific EIFS product and thus what the maufacturer wants. Generally what you describe sounds reasonable.

Woodpeckers may be just enjoying the noise-signaling property of your walls - and will continue to peck at them - or they could be after insects - less likely if you've had no leaks and no signs of insects. Check the opening for bugs before the repair.

On 2017-04-21 by Anonymous

@Chris p,
*wire Lath.

On 2017-04-21 by Chris p

I currently have a house installed with EIFS that is constantly bombarded with woodpeckers. One contractor said he could use long screws and attach wire path thru the EIFS and then apply a 2 coat stucco. I cannot find any literature if this is doable or if there might be issues with this install. Any comments would be appreciative

On 2017-04-16 by (mod) -

Bruce

In my opinion any sealant, even painted or color-matched, will not be an exact match for weathered cedar whose own colors will vary among boards and will vary further over time. You might use a paintable sealant and then stain the whole exterior with a pigmented stain. I'm doubtful that a synethtic stucco would work well in this application.

See https://inspectapedia.com/exterior/Wood_Siding_Staining.php - SIDING, WOOD CLEANERS, STAINS, PAINTS

On 2017-04-16 by bruceaballard@yahoo.com

I have an existing building with 1x6 Cedar which was put up green and has shrunk leaving gaps in between the boards. I'm looking for something that would fill the gaps and restore the surface like a synthetic stucco which is already colored is there a product for this

On 2017-03-06 by (mod) -

Susan,

The "right" answer to applying stucco to any surface depends on the stucco product or material type, e.g. traditional cementious stucco is applied differently and over a different base than modern EIFS or synthetic stuccos. But the underlying concept is the same: you either plaster a stucco coating directly to a beam (wood surface presumably) or for better adhesion you first nail or staple a substrate such as expanded metal lath or a synethetic fabric over which you then apply the traditional or synthetic stucco mix in on or several layers or coats.

On 2017-03-06 1 by Susan

How do I apply texture stucco on the underneath side of a horizontal beam?

On 2016-12-20 by (mod) -

Dave I don't think there's a single "right" answer, but where moisture penetration into a closed building cavity is a particular concern, Bliss and others prefer, as do I, closed cell foam as it doesn't pass moisture.

On 2016-12-19 by Dave

Would you recommend open or closed cell spray foam insulation for an EIFS/metal stud system wall in south Florida (zone 1)?

On 2016-10-28 by Anonymous

Great Idea Danjoe! Thanks.

On 2016-10-27 by (mod) -

Dean:

I like to use a ball of stainless steel or copper scrubber-sponge. The mice will not chew through that material. Then the exterior needs also to be sealed against air and water leakage using stucco or caulk.

On 2016-10-27 by Dean

Hi,

We saw a mouse running across the kitchen floor to underneath the oven.I think it went in the house through a gap (1/4 inch) from the outside where the wiring cable (1 inch diameter thick) enters the house on the ground level. The electrician should have seal the gap in the eifs wall but he didn't What is your recommendation material to seal those gaps off, they are quite large 1/4 to 3/8"? Thanks

On 2016-09-29 by (mod) -

Shary I can't see your stucco very well via etext (photos can be sent via the page bottom CONTACT link if you like) but I am *guessing* that a thin coating of stucco was applied over an expanded metal lath that's showing through. You might go to an unobtrusive spot and scrape away a bit of stucco to see if that's what's going on.

On 2016-09-29 by Shary

What is happening to stucco siding on an only 8 year old home that is peppered with small pieces of metal appearing to show through stucco? Please help!

On 2016-06-24 by (mod) -

Susan; usually a stucco contractor uses a cement-stucco mix to repair traditional stucco.

Search InspectApedia.com for STUCCO RECIPES & APPLICATION to read details

We don't know just what product your contractor used to repair your traditional stucco,

However Dryvit does produce stucco repair materials (acrylic-based) that the company says can be used to repair traditional stucco.
Dryvit Systems, Inc.
One Energy Way
West Warwick, RI 02893
800-556-7752
www.dryvit.com
Quoting from the company's literature

AC-100™, an all-purpose cement admixture, is ideal for use with patch and repair mortars, skim coats and stuccos.

- DRYVIT PRODUCTS FOR RENOVATION/RESTORATION DS212 (2016)

On 2016-06-23 by Susan

We have a real stucco home that has cracked and had water issues around the Windows. We noticed our contractor was using Dryvit brand to repair the stucco. Is this okay? I've heard lots of negative about Dryvit

On 2015-07-30 by (mod) -

I'd like to see photos of the walls - our email is at the page bottom CONTACT link.

If this is a wood framed structure you'll want to find the intervals of framing, remove stucco deep enough to accept the trim at the depth and reveal you want, and use exterior rated screws or nails to connect the trim through the under-layer of stucco into the structural framing.

if this is a masonry structure (stone, block, concrete) with a stucco skin you'll need to secure the trim to the structure using masonry fasteners. Rather than drilling and aligning lead anchors in the masonry, I like the Tapcon (R) system. You could drill right through the wood, into the masonry, using the special Tapcon masonry bit, then drive the tapcon anchors. But as you may not want to see the blue Tapcon screw heads you may need to counter-sink and plug the screw holes.

On 2015-07-30 by Chris A.

I am going to scrape off loose rocks from my beer-bottle stucco and apply a new finish coat. I'd like to divide the wall up with wood or hardiplank trim so that I can complete the stucco finish in each rectangle by myself. What is the best method for attaching the trim? Thanks for your help.

Question: so who can I get to install stucco on my home?

I enjoyed reading your report on stucco installation. I am in the process of taking the old stucco off my house in Brooklyn NY and installing new stucco. Most contractors I have spoken to have a blank stare when it comes to the true installation process. And they are supposed stucco contractors. Are there any stucco contractors you would recommend in the NYC Area,. Any help or recommendations would be greatly appreciated. Thanks. M.P.

Reply:

Thank you for the nice note, and of course the stucco question.

Sorry to say I don't have a specific stucco contractor to recommend, and more generally, even when we know of a contractor who has done great work in the past, as they say about the stock market, "past performance is no guarantee of future satisfaction" - I find that crew members and onsite managers can vary from job to job, with varying results even for the same contractor, unless it's a smaller company who always uses the same people.

Where that leads, also unfortunately, is that unless you are working with a known contractor whose worked for you before you pretty much need to learn a little about the topic yourself so that you can protect yourself from the wild arm-wavers who have never even read the instructions on the package.

Watch out: in a New Jersey synthetic stucoo failure court case I attended I was disgusted to hear that the prime contractor simply was ignorant or hasty and omitted critical steps and left out critical materials that would have insured a successful job. He did not follow the stucco installation recommendations nor standards provided by the manufacturer.

Yet when the contractor was challenged by the homeowner's attorney, he told the judge, who knew nothing about stucco, that the omitted steps were simply not included in his stucco job contract. The installation contractor omitted key details like backer rods and sealants that would have prevented serious building leaks, water and mold damage. He also failed to follow other installation requirements. His reply: our contract doesn't cover those components.

A typical homeowner would hardly know that something was being omitted from the stucco installation procedure. The least the contractor could have been done would have been to point out that omission and recommend how it should be addressed in order to get a successful stucco job.

Who the heck was supposed to install them then? It's as if you were buying a car and it was delivered without the motor. In my OPINION, you didn't get a car.

Question: thinking of buying a home with traditional 3-coat stucco exterior - was re-done over with synethtic, now it's cracking.

I am looking at a home for sale that has been built using Traditional 3 coat stucco. The owner had the stucco "redone" 5 years ago with a synthetic stucco which was applied over the traditional stucco. Now the stucco on the parapets (it is a pueblo style home in the southwest) has cracked and in rain the traditional stucco underneath has become wet and turned to mush.

I would like to remove all the synthetic stucco coating and get down to the traditional stucco and REDO THE STUCCO ON THE ENTIRE HOME USING TRADITIONAL STUCCO.

The stucco company in my area says that the only way to go back to traditional stucco is to re-net (put new lath) on the home and then apply a base coat, wait 2 weeks and then put the traditional stucco color coat on. Is this the only way or can the synthetic stucco color coat be removed by a process such as sandblasting? - Patty 9/17/11

Reply:

Patty, I suspect that the overcoat of synthetic stucco did not include the manufacturer's recommended backer rods, sealants, and protection at penetrations. Once water gets behind synethetic stucco, as you have unfortunately found out, it stays there, causing trouble. This stucco job is in serious trouble.

I am afraid I agree with the stucco company you consulted. Mechanical removal of the problem material is what's needed, along with an investigation to be sure there is no rot or mold that needs to be addressed.

Reader follow-up:

Thank you Dan,

The stucco company told me this is what they consider to be a failed synthetic stucco. They stated that the company who had redone the stucco for this home using a synthetic stucco over the traditional stucco had likely not followed manufacturer's instructions to properly use the appropriate mesh over the parapets and to prime the home.

They have given me estimates of 15,000 to redo the stucco using a synthetic stucco product or 25,000 to re-net (rewire) the entire house and do a traditional stucco job.

This is only a 1,400sq foot home with a 2 car garage. The seller of the home did not know whether the stucco was synthetic or traditional stucco and likely she did not understand the problems that could occur from having a company use synthetic stucco instead of redoing the home with traditional stucco which would have been less costly and given a better result.

I have decided not to proceed with the purchase of this home as there is too much water damage to the parapets. Thanks again! Patty

Opinion:

Patty:

It would be unusual to find a defect that would be so costly that it makes buying the home out of the question, but nevertheless it's important that you have as accurate as possible assessment of the home's condition, needs for repairs, and priority of repairs so that you have an accurate picture of the home's true cost:

True home cost = purchase price plus the cost of repairs that are necessary for the home to be safe, functional, and not rapidly deteriorating.

If the true cost greatly exceeds the purchase price or the projected near term value of the home once it has been repaired then the deal may not make sense. For example, I inspected a home in Beacon NY that was selling for $125,000. in a neighborhood of $100,000 homes and that needed another $50,000. in urgent repairs.

The deal just didn't make sense unless the buyer had great reason for going ahead and if s/he expected the home to remain in the family for generations.

Under the aegis of that advice, if you were to decide to buy a home such as the one you describe, your home inspector should form an opinion about the level of risks of leaks into the structure and a possibly costly hidden mold or rot or insect damage problem.

A problem with inspecting stucco-covered homes is that there can be hidden damage that does not quickly show up in the forms of cracks, movement, etc.

Question: stucco over wood shiplap siding?

We are in Sacramento, CA. Our home was built in the 40s and skinned with redwood shiplap siding. We would like to stucco over the siding for a more durable finish. I have 2 questions:

(a) I recently learned about stucco rainscreens applied behind the stucco to better manage water against the sheathing. Is it necessary or an "extra." I was going to apply a layer of Tyvek stucco wrap as a water proof membrane then follow std procedure with 2 layers of grade D 60 min paper. I'm thinking of the South and West walls which gets the most rain and sun. Can you comment on this?

(b) If we like the look of wood trim over the stucco around the windows, my understanding is that we could either leave the existing 1x4 trim and stucco to it or take out the trim and stucco to the window. In the latter, the wood trim could be applied over the stucco for aesthetics.

Can you comment on each option - pros/cons and best practices for minimizing water leakage from trim applied over stucco. - Sherman Wong 10/25/2011

Reply:

I would not apply stucco to the building without, for the specific stucco method you like, reading the manufacturer's specifications in detail, as they vary. The particular rain screen type and installation and requirements vary, for example.

About stuccoing up to trim, you might want to test that approach on one section of your home. You may not like the aesthetics of the windows and doors beginning to recede into the skin of the building.

And in any event, review the stucco manufacturer's advice for proper sealing around all of the building trim - leaks into the walls at trim, and trim rot, are common problems on many stucco'ed buildings, both with the traditional stucco methods and with the EIFS methods.

Question: one-coat stucco on concrete block

Thank you for all the good information. Here in Florida the standard practice seems to be to apply one coat of stucco directly to the concrete block walls ( no lathe ). They seem to use various trim pieces or corner moldings out of styrofoam ( i think ) or plastic. The stucco is cracking open at the vertical corners, probably from heat expansion of the plastic. Is there an accepted repair method for this type of failure? - BGrubert 11/22/11

Reply:

Bugrubert:

from your description I wonder if your wall needed an expansion joint or two. Before repairing the stucco wall by cutting, patching, repainting, it would be a good idea to check with the particular stucco system manufacturer and compare the wall dimensions with their specifications to see if you need one or more control joints. I'd also double check that the cracking is only in the stucco, not in the underlying masonry block walls.

Question: troubles with stucco contractor

I have a bully contractor who has dragged his feet on the job and now is in a hurry to finish a large room and is not even allowing 24 hours between the middle coat and top coat. I was told that it didn't matter that it will all cure at the same rate. he is using a stucco cement with stucco sand added and no bonding agent. it is applied to wire mesh on old cedar lath walls in a fram house. By tomorrow he will be back to work and my ulcer will be flairing up --- Thanks I will look for a reply. - itmaybetoolate 5/9/12

Reply:

Maybe - you need an onsite consultant who is an expert and who can help you deal with your contractor.

Question: acceptable viewing distance for examining a paint job

What is the acceptable distance to view an exterior paint finish. I know painted concerete is approx 20 ft away not noticing holidays? Any comments? - BigBee 5/15/12

Reply:

Good question, I don't know but will look for some standards. If you can cite any let me know.

Question: Exactly how do we apply stucco to our house?

We are building a house w stucco exterior. what are the steps? So far we have plywood in place. And will be doing Tyvek. When do windows and doors get installed? - Kim 6/24/12

Reply:

Kim,

eek, this is more than I can answer as a simple reply to an e-question. But for a very detailed exposition on exactly what steps are involved in applying stucco to a building, contact the manufacturer of the stucco system that you are going to use. Every stucco system manufacturer provides very detailed and clear specifications for how their product should be installed.

Windows and doors and their flashings are installed when the building sheathing is in place.

These questions make me worry further that you are building a house with no experienced builder supervising the job.

And incidentally, most residential stucco leaks and failures seem to be traced to failure to follow the instructions to the letter.

Question: how do I use stucco to close off gaps in a fireplace wood storage areas

..i want to use stucco to close off gaps in the inside fireplace wood storage area..i have a brick fireplace with a wood storage area to the right..facing the fireplace it appears to all be solid brick..but when you get down to floor level and crawl inside the bricked wood storage area you find the brick work near the 'ceiling' stops about 2 layers in..then another layer of brick but with a 1-2 inch gap..i can feel cold air coming in here during the winter..

can i just stuff wire mesh tightly in this gap and then apply stucco..perhaps in layers to seal this off?

don - Don 8/20/12

Reply:

Don:

The setup you describe makes me a little nervous about who built the fireplace and where else s/he may have left air gaps that might be unsafe. And as for Chuck, I don't quite get the picture - about the - 2 layers in - but in general, and assuming we're not messing with some wierd combustion air supply scheme,

and provided that we are NOWHERE near the firebox itself (as there you want solid masonry, no?) if you seal that leaky air gap with a fireproof material such as wire lath and stucco that should be ok.

Question: how do I stucco over bare studs in a shed?

I want to stuco a shed over bare studs could you help me with the prosses - Chuck King 11/29/2012

Reply:

Chuck,

It's a bit risking giving detailed instructions about a building and site we know absolutely nothing about. So I demur.

But in general, if you are stuccoing over bare wall studs on a building exterior, building sheathing is needed first; probably then you'd use either an EIFS method or a traditional wire lath method.

If you are stuccoing indoors on an un-finished wall in a storage shed, there are plenty of options that are quicker and easier, like nailing up plywood or another sheathing board. If nevertheless you want to apply stucco, you might look at the expanded wire lath method.

Question: is a 1/2" or greater air leak at the bottom of a stucco'ed wall "normal"?

(Jan 13, 2013) Alex said:

Hello. I purchased a new construction home in southern California where the builder used the one coat stucco system. The problem I have is throughout the perimeter of the home, there are more places than not where I can fit my fingers if not my hand behind the weep screed and the foundation/ framing 2x4s.

My builder said it is normal but it is causing problems with cold air in the winter and hot air in the summer to drastically change the temperature inside my home as well as insects. I don't know anything about stucco but I do know this is not acceptable to have the framing of my home exposed to the elements. What is your take and or recommendations for my problem? Thanks Alex 1.13

Reply:

Alex, when your builder describes as "normal" an air leak at the wall bottom that is big enough that you can stick your hand into the opening, I am led to the OPINION that it may be normal for him or her, but it's not good construction. Someone needs to take a closer on-site look at exactly what's going on before prescribing any repair steps.

Question: comment:

(Feb 1, 2014) (mod) said:

Re posting an anonymous comment without hyperlinks (not allowed, for security reasons)

We build new homes in California and have switched to stucco trim products It is a non foam product. It is a wire mesh shape that becomes solid.

Question: chalking around windows on a stucco home

(Mar 18, 2014) Dusty said:

On a new construction, should you chalk around all windows on an all stucco house! Also, over time some separation is notice between stucco and window casings. Should this be chalked?

Reply:

Dusty,

If by "should you chalk around" you mean drawing chalk lines, I have no idea and don't know what you're after.

If you mean should there be white efflorescence markings or deposits on the exterior, that defect may indicate a leak into the walls or it may indicate improper painting or coating. Near the top of this article to right of the first photo click on

SIDING EIFS STUCCO PAINT FAILURES - separate article - for more examples and explanation.

Question: is there any problem with using a synthetic like STO on the parapets, and traditional stucco everywhere else.

(June 8, 2014) Doug said:
The parging has cracked/broken off my foundation walls, there is a thin layer of tar on the concrete wall all the way up to the stucco. I can't remove the tar because its sealing the wall from moisture. So is there a bonding agent or membrane I should apply before trying to get the parging to adhere to the wall?

(June 13, 2014) Nitin B. PAtil said:
i want to such as product which is applicable for filling the gaps between wood frame and RCC/Brick work

(July 27, 2014) Gil said:
Our home currently has traditional cement and lime stucco. We live in the high desert of Albuquerque, New Mexico.

We have trouble with cracks that develop mainly on the parapets, which protrude out a few inches for a decorative effect. I am wondering if there is any problem with using a synthetic like STO on the parapets, and traditional stucco everywhere else.

We would use an accent color for the parapets, probably a darker shade of the cement stucco color, so we do not have to worry about trying to match the cement stucco. My hope is that the synthetic would have more resistance to cracking, but I would not need to worry about moisture being trapped by the synthetic if it is just being used on the parapets.

Reply:

Gil,

My OPINION is that it should be fine to use synthetic stucco for different segments of the construction that abut as you describe *provided* the transitions are flashed, sealed, or otherwise treated per the stucco system manufacturer's specs.

Generally the worst problems with moisture intrusion into synthetic stucco systems is at un-sealed penetrations in the EIFS membrane. Since your parapets would not have penetrations (such as for lights, windows, etc) the risk is minimized.

Take special care at the juncture of parapet to roof and parapet to wall at its overhang joint.

Also check that the cracking you are seeing is not due to poorly-constructed parapets that are sagging or moving.

Question: Which stucco method is more durable?

(July 29, 2014) Bruce Fitz-Gerald said:
I am looking to have the stucco redone on my house. The original stucco was done when the house was built in 1951. The stucco was applied directly to cinderblock walls. I have two quotes currently. The first is using foam board adhered to the existing walls with galvanized nails and then scratch and stucco layers applied. The second quote is to powerwash the existing walls, chip away any loose material and then apply mesh with galvanized nails, scratch and stucco layers.

Of the two methods, which one is more durable? Does the foam board make the walls softer? and finally, what needs to be done so the foam board does not become saturated with water?

Reply:

Bruce, I'm not of the OPINION that there is a single right answer to your interesting question. For all stucco systems the devil is in the detail of application - did the installer follow the stucco system specifications?

Stucco on block is indeed less vulnerable to impact damage; it's also less vulnerable to moisture leaks into the wall cavity that can occur on some synthetic stucco systems installed on wood-framed walls, but as your walls are solid block the concern is likely minor.

Stucco on foam boards, properly installed is quite durable. I don't worry about moisture entering the foam boards provided the installer uses the foam board (and all other components and sealants etc) recommended by the manufacturer of the stucco system they are going to use.

There may be an added advantage (depending on where you live) of having some insulation on an otherwise uninsulated block wall.

Question: Which stucco is better, traditional or synthetic

(Aug 25, 2014) Linda said:
We live in the Albuquerque area and have a 15year old home with traditional stucco.

When we do a redo on the stucco and parapets...everyone has a different opinion as to which is better, synthetic or traditional. People who have put synthetic over traditional have not had problems over a couple years, but I wonder what will happen in the long run.

Should we stick with traditional? What is the truth,it seems to depend on the contractor and what he wants to do.

Reply:

Linda as I opined to Bruce just above, the truth lies here in the skill and care of workmanship. IF the contractor is very expert in a particular method naturally it's safer to let him or her use the most familiar method.

Complaints about EIFS failures are usually traced to leaks in the system that are usually blamed on the contractor not following the (arduous, demanding, hard to follow in all details) specifications from the manufacturer.

Applying synthetic stucco over existing old-stucco on wire or wood lath? I'd be cautious about mixing materials and approaches. We will do some research on that hybrid approach.

Question: sealant for stuccos, Stucco in Oklahoma, Stucco in San Diego CA

(Oct 9, 2014) Keith said:
Hi,

I have some stucco siding that needs repair. During a back yard reno I found the landscaping elevation was above my walk-out basement floor slab, resulting in seepage and rot beneath the lower portion of my stucco siding. I removed the lower 24 inches of stucco and from that determined 16 inches of rotted boarding needed to be replaced, which I did with green treated plywood.

I have double wrapped the area with Grade D paper and it is ready for stucco.

One issue is there is no room beneath the exiting stucco to allow for a proper lap of the horizontal seam of the new house wrap. I have however attached the new house wrap as tight as possible against the lower edge of the existing stucco.

And the repaired area will be parged rather than trying to match the 20 year old stucco colors. Will I have a problem with the house wrap not being underlapped with the existing stucco ? Or is there a sealant I could use to mitigate the potential problems of not haveing a proper underlap ?

(Oct 23, 2014) John said:
Hi, we are living in Noman, Oklahoma and are planning to build a new home in Spanish Revival style over the next year. We have lived in a Spanish Revival house built in 1937 with traditional stucco that has seemed to hold up fairly well. Our builders have used EIFS with drainage for years on wood frame homes and prefer that over traditional stucco.

What do you think would be the best choice for stucco in my area of the country. We have 4 definite seasons with hot summers often over 100 degrees and cold winters with freezing temperatures. I have even thought about using stucco over brick. Thank you for your help.

(Nov 4, 2014) Karen C said:
Hello. My 1950s tract house in San Diego, CA had some stucco damage near the bottom in a few areas. The damage was repaired and the house stuccoed with a scratch and finish coat. There is no weep screed. The house' roof has a small overhang and no gutters, so the rain hits close to the foundation and had caused a trough that fills with water when it rains substantially

. In preparation to have the house restuccoed, I dug the soil out 6" down and 6" out from the foundation. Now I am trying to prevent the new stucco from taking up water from the soil and mud splashing onto the stucco when it rains. The house is at the top of a small hill so drainage is generally good.

Do you have any suggestions? How good would it be to install an apron of gravel, concrete or pavers that meet the house and angle away to direct water away from the stucco? Thank you.

(Nov 6, 2014) omar said:
can be stucoo aplied to an adhered thermal insulation on a concrete wall ?
i mean will the adhered insulation hold the wait of the stucco?

Reply:

Karen

Be sure that the roof gutters are kept cleared and working.

Walk around the house during heavy rain to see where water is going and thus what might need repair.

Keep 6" or more between the ground surface and the bottom of any siding material that could invite termites or carpenter ants into the structure.

With working gutters and downspouts, good surface drainage, and proper ground clearance, and with the wall finish sealed with paint or another approved stucco coating, the remaining splash-up from rain itself ought not be an issue.

Omar

you'll need to apply a mechanically-adhered mesh to support the stucco system.

Question: for supporting stucco, which mesh is better, steel or fiberglass ?

(Jan 8, 2015) Craig said:
Greetings,
I have an old building the first floor is block, however the second floor is corrugated fiberglass. Is it possible to stucco over the corrugated fiberglass?
Great articles, Thanks for the information.
Craig

One more, please..
Should I use a steel mesh, plastic or fiberglass mesh?

Reply:

Craig: You will need to mechanically adhere a mesh to apply stucco.

Steel diamond mesh - which cuts the installer easily - has more rigidity and may be needed over irregular surfaces like a corrugated surface. But ultimately you want to select a mesh type recommended by the manufacturer of the particular stucco product you are planning to use.

Generally we see steel mesh with traditional stucco and fiberglass mesh with modern EIFS or synthetic stucco systems.

Question: water leak at horizontal stucco joint

28 January 2015 Ken said:

I have a water leak about 2 feet over the top of a window and I suspect there is water intrusion at the control joint which runs horizontally over this window. The stucco is over the control joint channel, which I guess is for asthetic purposes. Can the control joint be sealed and somehow made waterproof and if so what would be a good product? Traditional 3 coat stucco.

Reply:

Ken

I'd need to see installation details to be confident in advice about the leak you describe, but generally you'd expect horizontal zee flashing at a horizontal stucco control joint. Just sealant alone may not be reliable.

If you know the brand and type of stucco system that was installed we can (either of us) take a look at exactly how the stucco manufacturer wants the joint treated - they have the best say on the matter.

Question:

(Apr 9, 2015) Kathy Machir said:
The picture of San Miguel de Allende, Mexico could almost be ours as we also live there. Although our house is only 6 years old, we have repaired cracks which do not hold, repainted with two coats of acrylic paint over freshly repaired cracks, and continue to have the paint peel off.

The house is a traditional brick house with thin plaster coating.

I have read through your many analysis',recommendations, etc., until I am ready to cry "uncle". This is clearly not a job for a traditional Mexican contractor. As you have access to a photo of San Miguel, and understand the building issues here, by chance do you have a contractor you could recommend to use for this project?

Reply:

Kathy,

You are welcome to contact me by email - found at the CONTACT link at page top or bottom. You can send me some photos of the home and of the leaks or cracks and I maybe able to offer comments; or I may be able to take a look at your home myself - directly - and make some suggestions.

Typically you need to find and fix the moisture source: leaks from the other side of a wall or from a roof.

Question:

(June 5, 2015) Cam said:
I built a traditional adobe wall with doors, windows, buttresses, curves, etcetera - 150 feet long, 6' high - a 2 summer art project. The intense rains here in Colorado have been slowing eroding it, so decided it was time to stucco. Exchanged a contract which provides for metal lathe and two coat application.

Came home from work yesterday to find the contractor and 5 workers had applied the first coat directly to the adobe wall with no mesh. It rained like crazy last night, and the first coat is cracking and peeling. I discussed the metal lathe with the contractor before the work began. What would you suggest be done at this point?

Can they put the metal lathe on now and re-coat, or does the first coat have to come off and start over?

(June 18, 2015) jackiecimento@msn.com said:
We are contemplating having some stone planter boxes installed in front of our stucco home.

The landscaper suggested using the house as the back wall of the planter by installing a water sealant to the areas where the soil will be against the wall. Would you recommend an elastomeric waterproofing membrane, or liquid water proofing membrane, or advise staying away from the idea altogether?

(6 days ago) Darcy Saby said:
We have built a stucco wall and placed a wood cap on top. There is now a gap between the top of the wall and the wood in some places. What should we fill the crack with?
Thanks!

Reply:

I'd use a latex-based sealant that is formulated to resemble the stucco in texture and colour, or one that is paintable to match. Some of the concrete patching sealant/caulk products might suit.

Question: builder left out the weep screeds

I have just built a modern home with first floor (slab on grade) stucco exterior. I've had some difficulties with the builder. After final inspection - it was noted that there was no "weep screed" The builder said for cosmesis - it was under the stucco. It seemed fishy and after a few go arounds between lawyers, he agreed to remediate the stucco.

When the stucco was off the house - I took pictures and there was no metal lathe under

-- it was placed by the stucco vendor secondarily and a screed now exists for 90% of the house. He ignored several small sections (reverting to his assertion that the screed exists - it's under the stucco and the remediation he agreed to was just for cosmesis)

This yard is very wet and I can't believe that some of the stucco, but not all, needs a vapor escape system. MN Lathe and Plaster won't let me pay them to come and give an opinion. The city inspector (who passed the house initially) is not willing to comment... so I am left to believe the builder who has been untruthful about the project from the beginning. Please advise. - 6 July 2015 Anon

Reply:

Please see STUCCO WALL WEEP SCREED DRAINAGE where there are details about this case.

...

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• STONE, STUCCO & BRICK CLEANING METHODS

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