Stucco hairline cracks

[Vern Heiler]

6 year old house has small amount of hardcoat stucco on wood frame and a few hairline cracks that look like shrinkage. Can these be repaired with a fog coat? Or would you call them cosmetic?

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[CHARLIE VAN FLEET]

whats up with that large clob of vertical caulking on first picture--never seen that before--except for repairs--typical cracks to me

cvf

[Vern Heiler]

whats up with that large clob of vertical caulking on first picture--never seen that before--except for repairs--typical cracks to me

cvf

How would you join brick to stucco? Do you have a size of crack that calls for sealing or repair in stucco field?

[John Kogel]

Do you have a size of crack that calls for sealing or repair in stucco field?

Vern, cracks that narrow are probably best left alone. If there's a roof overhanging those areas, it is no concern to have a few surface cracks as a rule.

There is no invisible patch for such cracks, or maybe there is, but I've never seen them.

[Ian Page]

Elastomeric paint - color matched to the stucco, will bridge hairline cracks as depicted (and larger). A decent quality masonry paint would work also but it's not as flexible.

[Scott Patterson]

Elastomeric paint - color matched to the stucco, will bridge hairline cracks as depicted (and larger). A decent quality masonry paint would work also but it's not as flexible.

Stucco or for that fact any masonry product should never be painted with a plasticized(elastomeric) paint. When this is done you have essentially made the masonry a barrier cladding, it no longer allows for water vapor to dry. In a few years you will then see bubbles, spailing, and sections of the masonry flaking off.

Yes, they do formulate paint that can be used on masonry

I would not worry about the cracks. Stucco is a concrete product and concrete does two things. It shrinks and cracks as it cures and dries.

[Peter Louis]

I like to hear comments on that caulking.

[Ian Page]

Yes Scott...I know the pitfalls and wasn't suggesting the whole house or all the stucco be painted but elastomeric paint does serve a purpose in small areas where hairline cracks are present. I have used it myself, sparingly, for many years over stucco finishes without any problem whatsoever. Though that may, in part, be due to the temperate So. Cal. climate.

I think there are companies who still advertise locally, using elastomeric paint as a whole house protection over stucco finishes, though I personally don't 'buy' into that application.

[Rod Butler]

Elastomeric paint - color matched to the stucco, will bridge hairline cracks as depicted (and larger). A decent quality masonry paint would work also but it's not as flexible.

I had my entire house in Saint George Utah painted over with an elastomeric paint. That was in 2004 and have had no problems since. It covered up the cracks well. I went on the recommendations of the local painters and it looks great.

I hope I didn't select the wrong product.

[BARRY ADAIR]

pick your solution

Stucco Manufacturers Association - Technical Papers

[Robert Ernst]

I'm not a fan of the elastomeric paint. It has to be applied to the proper thickness which is something that doesn't happen often. I have seen it fail here or have water behind it. On new construction around here most of the stucco is painted so they just go back and repaint the small cracks.

[Rolland Pruner]

Vern. These are typical cracks found in stucco, remember any concrete product: the only gaurantee you get it will crack!! I would leave alone and the next time to paint I would use a 100% laytex paint it will cover well and expand with cracks (unless major) this would do the job.



Rolland Pruner

[Aaron Miller]

pick your solution

Stucco Manufacturers Association - Technical Papers

I like fog coating. Yes, I know, everyone else likes painting stucco. That's fine, as long as it is yours. I will not paint mine.

[Billy Stephens]

.
I had my entire house in Saint George Utah painted over with an elastomeric paint. That was in 2004 and have had no problems since. It covered up the cracks well. I went on the recommendations of the local painters and it looks great.

I hope I didn't select the wrong product.

.
No Worries about moisture getting trapped behind it there.
*With less than 8 inches of Annual Precipitation .
.
St. George, Utah - DesertUSA
.

[Jerry Peck]

I like fog coating. Yes, I know, everyone else likes painting stucco. That's fine, as long as it is yours. I will not paint mine.

I would, will, and have painted my stucco on my houses.

I have even painted parts of the walls with elastomeric to reduce the moisture load on the walls from seeping through the stucco and the walls - and it was successful and not only did not cause any problems, it solved the existing problem of the stucco/block not drying out.

We bought a house in South Florida which seemed like it leaked at one wall, but after removing and replacing, resealing the windows, etc., I could never find any evidence of leaks. I surmised that the wall had been saturated during Hurricane Andrew and that, because stucco on masonry is a get-wet-storage-and-dry-out system, the wall was never able to dry out. Thus each rain would cause the wall to become re-saturated and seep water through the wall.

I painted approximately 80% of the wall surface with elastomeric paint (I dislike elastomeric paint, but realize it has its uses), leaving the top and bottom foot or so of the wall not painted with elastomeric so it could breathe, and painted most of the wall area between. That reduced the moisture load the wall could be wetted with each rain, and allowed the a/c to dry the wall out from the inside.

It worked. Problem solved.

I discourage painting with elastomeric paint, but there are limited uses for it, at least in my opinion.

[Aaron Miller]

Why would one want to violate the principles of a breathable, self-draining wall and seal it up, risking all of the potential consequences which that entails? A color coated stucco requires no maintenance (other than occasional cleaning and resealing the joints), no repainting, and if properly constructed, is essentially waterproof. An elastomerically coated wall has to be maintained and repainted periodically, is at risk of sealing moisture into a dual barrier, and risks mold from both interior and exterior moisture. It is much harder to properly install elastomeric paint, i.e. to spray, backroll, and then cover all pin holes, than to properly flash and build a conventional three-coat stucco wall. Hairline cracks are not a problem with three-coat stucco since the waterproof barrier is behind the surface, not at the surface itself. If the three-coat stucco wall was originally properly constructed and hairline cracks are offensive, fog coating is a much less expensive and long lasting alternative. If the stucco was improperly constructed, it seems the prudent thing to do to remove it and rebuild it, rather than to paint it with a coating that has to be constantly maintained.

[Phil Brody]

I would, will, and have painted my stucco on my houses.

I have even painted parts of the walls with elastomeric to reduce the moisture load on the walls from seeping through the stucco and the walls - and it was successful and not only did not cause any problems, it solved the existing problem of the stucco/block not drying out.

We bought a house in South Florida which seemed like it leaked at one wall, but after removing and replacing, resealing the windows, etc., I could never find any evidence of leaks. I surmised that the wall had been saturated during Hurricane Andrew and that, because stucco on masonry is a get-wet-storage-and-dry-out system, the wall was never able to dry out. Thus each rain would cause the wall to become re-saturated and seep water through the wall.

I painted approximately 80% of the wall surface with elastomeric paint (I dislike elastomeric paint, but realize it has its uses), leaving the top and bottom foot or so of the wall not painted with elastomeric so it could breathe, and painted most of the wall area between. That reduced the moisture load the wall could be wetted with each rain, and allowed the a/c to dry the wall out from the inside.

It worked. Problem solved.

I discourage painting with elastomeric paint, but there are limited uses for it, at least in my opinion.

That's a very interesting solution, not sure the unsealed section at the bottom is necessary to create a convection mechanism, guess you would never know if painting the whole wall would have resolved the problem as well.

[Jerry Peck]

Why would one want to violate the principles of a breathable, self-draining wall and seal it up, risking all of the potential consequences which that entails?

Why would one call stucco on masonry self-draining and refer to stucco on masonry as having a principle of self-draining? Unless one is confused and is thinking of stucco on frame ...

It is much harder to properly install elastomeric paint, i.e. to spray, backroll, and then cover all pin holes, than to properly flash and build a conventional three-coat stucco wall. Hairline cracks are not a problem with three-coat stucco since the waterproof barrier is behind the surface, not at the surface itself. If the three-coat stucco wall was originally properly constructed and hairline cracks are offensive, fog coating is a much less expensive and long lasting alternative. If the stucco was improperly constructed, it seems the prudent thing to do to remove it and rebuild it, rather than to paint it with a coating that has to be constantly maintained.

Additional evidence that one is thinking of stucco on frame and not stucco on masonry ... I said:
- "it solved the existing problem of the stucco/block not drying out."
- "because stucco on masonry is a get-wet-storage-and-dry-out system"

[Jerry Peck]

... guess you would never know if painting the whole wall would have resolved the problem as well.

You are correct that I will never *know* if painting the whole wall would have worked , but the fact that elastomeric paints reduce the movement of moisture vapor considerably, I *know* that would have reduced the ability of the wall to dry toward the outside and all drying out would have had to take place from the inside by the a/c, and in South Florida the a/c runs enough to suck the moisture out of the wall if the moisture is not being replenished too much.

Stucco on masonry is a get-wet-storage-and-dry-out system. The wall needs to be able to dry out to the outdoors (from the sun and air) and from the inside (the a/c).

My intent was to reduce the moisture load on the wall from outside forces, then let the system work as it was designed to work.

[Aaron Miller]

JP: Yes, I am aware that a very small percentage of our citizens live in concrete block houses. I empathize with them.

The comment was intended for the majority of us who live in affordable housing by way of a government subsidized lumber industry.

[Rod Butler]

After thinking about this a bit more I think the elastomeric paint has more benefits in a humid climate than it does in my dry climate. It has to more to do with the placement of the vapor barrier. Any contractors from the Southeast might chime in here and correct me of wrong.

In Utah the vapor barrier in a structure is typically placed on the inside of the wall to prevent humidity from the space from entering the cavity. However in humid climates it's my understanding that the vapor barrier is best suited at the exterior because the moisture content of the air is higher than the interior. Condensation is therefore kept out of the insulating space.

[Jerry Peck]

JP: Yes, I am aware that a very small percentage of our citizens live in concrete block houses. I empathize with them.

The comment was intended for the majority of us who live in affordable housing by way of a government subsidized lumber industry.

I, too, now live in a flimsy house constructed from sticks up here in Ormond Beach.

And that is the key ... "up here" ... "in Ormond Beach" ... versus down there in South Florida where those things called high wind events happen on a much more regular basis.

Down there ... the Big Bad Wolf comes and huffs and puffs and blows your house down if it is made out of sticks.

[Aaron Miller]

I, too, now live in a flimsy house constructed from sticks up here in Ormond Beach.

And that is the key ... "up here" ... "in Ormond Beach" ... versus down there in South Florida where those things called high wind events happen on a much more regular basis.

Down there ... the Big Bad Wolf comes and huffs and puffs and blows your house down if it is made out of sticks.

After the thirteen tornadoes that went through here a week or so ago I am lusting for a concrete house.

[Vern Heiler]

I've been letting this soak for a while now and have been pondering all of the good post, that I appreciate from you all. The one thing I would still like to know is what size crack does it take to be called out by most of you? The buyer of the house in the original post was one of the very picky type that had me a little concerned that she might have been studying my liability insurance rather than my derrière. I normally don't let anyone influence me on what goes in the report but not having a size of crack to fall back on, I recommended fog coating. Probably won't stop any more moisture from entering the wall and probably won't get done but the CYA buzzer was going off.

For the next time does anyone have a standard for acceptable cracks in stucco?

[Scott Patterson]

I've been letting this soak for a while now and have been pondering all of the good post, that I appreciate from you all. The one thing I would still like to know is what size crack does it take to be called out by most of you? The buyer of the house in the original post was one of the very picky type that had me a little concerned that she might have been studying my liability insurance rather than my derrière. I normally don't let anyone influence me on what goes in the report but not having a size of crack to fall back on, I recommended fog coating. Probably won't stop any more moisture from entering the wall and probably won't get done but the CYA buzzer was going off.

For the next time does anyone have a standard for acceptable cracks in stucco?

I look for a pattern in the crack(s), those spiderweb type cracks do not alarm me. By pattern, I mean more vertical or diagonal and not in the middle of a wall with no penetrations. Then I look at miter cuts on trim to see if they are showing signs of stress or movement.

Honestly it is more of a feeling based on what I have seen over the years.

[Aaron Miller]

For the next time does anyone have a standard for acceptable cracks in stucco?

Cracks in Stucco: Investigation and Repairs - Feature Article - Walls and Ceilings

[Vern Heiler]

Cracks in Stucco: Investigation and Repairs - Feature Article - Walls and Ceilings

Thanks Aaron