My house has stucco wall. Few month ago I had it painted with
elastomeric paint. Today we had our first major storm of the season,
with winds blowing the rain side ways hitting the southern wall. I am
in San Francisco bay area.
After the rain, I noticed part of the wall have lots of bubbles. Some
are small, some are larger.
Here are some pics:
I only see this on the southern wall. The rest of the house seems ok..
Googling a bit, this indicates water has gotten behind the paint, and
are pushing the paint out?
Did I made a big mistake going with elastomeric paint on my house? Did
the painter do a bad job? What do I need to do to fix the problem?
Please help, the raining season has just started.
Our condo has stucco on concrete block, Florida. When the condo was
painted, we got an estimate for elastomeric, recommended by that one
particular contractor...tremendously expensive. Ended up with acryllic
latex, one coat primer, one coat paint. In researching paint issues,
some authorities rec. using a pin to puncture small bubbles. Piercing
the bubbles allows water or air/gases to escape, leaves paint film
intact, and all MIGHT be well.
How old is the home? How many coats of paint? Stucco on what? Pressure
washed? Primed? After 2005 hurricanes in Florida, there were a number
of news articles addressing the issue of rain being forced through walls
by the wind - older homes didn't suffer as much from that particular
problem because they had more coats of paint and therefore were better
protected. Most homes in Fl. are stucco on concrete block.
Any idea of how forceful wind was? It would be worthwhile to contact
the paint company and your insurance company. When our condo was
painted by a contractor, the paint co. inspected the prep work and the
final finish. Probably not something they do for single fam. homes.
The house is 50 years old. The painter power washed the wall, and put
on 1 layer of kelly moore elastomeric paint. I think it has kelly
moore regular exterior paint before.
The wind was big. news was saying "Strongest October storm since 1962
pounds Bay Area".
After painting a few month ago, I realized the paint feels different.
Before, if I scratch something against the wall, I see a mark. After
painting, it scratches off the paint. I thought it was the properties
of the elastomeric paint, feels like a thin plastic layer.. could it
be it didn't stick well because only one layer and no primer? Or is
elastomeric paint suppose to behave this way?
I am going to call the company tomorrow to see what they say. At best
they may offer to repaint the southern wall. But my question is, is
elastomeric the wrong choice for stucco wall (doesn't allow it to
breath, and hence introduce molds and all kinds of crap and ***$ up my
house, or did the painter simply didn't do as good of a job, and let
water get behind it?
Will re-prime, and re-paint fix the problem? or simply re-paint with
more elastomeric paint? or just regular acryllic paint?
If new paint scratched off that was your warning something was done
wrong. What you are I think saying is it didnt bond to the old finish
and is comming right off. If thats the case then a simple repainting
wont do anything to fix the issue, removal of all loose paint is
needed. The reason has to be figured out. I would call the store that
sold you the paint, the paint co, and of course the painter who will
deny its his fault. Does Elastomeric paint breath?, is it recomended
for stucco?. For about 50$ you should get yourself a moisture meter,
everyone is going to say its your problem, you have water in the
stucco. But if it peeled off from day one id suspect its poor
aplication, as in it was put on a sun heated damp-wet surface- from
washing, and possibly it was the wrong product to use from a
breathability standpoint, [ breath ability] of the product would havbe
a tested rating by kelly moore. I will bet the stucco was wet from
powerwashing, the sun heated it just after it was painted, or the
surface was hot from the sun and it never bonded at all, and a
moisture reading now wont be excessive after a big rain.
Not familiar with moisture meter. Is this what you are talking about?
I use it to measure moisture trapped inside the stucco?
Sonin 50218 Digital Moisture Meter
(Amazon.com product link shortened)55555412&sr=1-6
The paint didn't peel off (day one or now). In fact everything looked
fine until yesterday. No cracks or peels. I didn't buy the paint, the
painter got the paint. This was painted back in July, where it's
pretty dry and warm here (~80 during the day, 60 at night). I recall
they power washed in day 1, caulked all the cracks, etc. day 2 was
prep, put plastic over windows, etc, and start painting. day 3
finished painting. I don't remember exactly whether they started
painting at end of day 1 or day 2, but the troubled wall was
definitely painted in day2 afternoon. so it should be dry, but it
might be hot from the sun.
At the time I felt like they did a pretty professional job. All the
prep work, painting and clean up afterwards is pretty good. No peeling
or cracking what so ever until the bubble on the southern wall
They used a spray gun, and possibily roller. One thing I noticed was
they got some water from the yard when they were painting. I wasn't
sure if it was for washing the supplies, or did they add water to the
mix. When they were wrapping up the job I did saw a bucket of dirty
water which they washed things.. IF they had mixed water into the
elastomeric paint before spraying, could that have caused it not to
stick as well?
What I meant was. I feel the elastomeric paint is a like a rubber
layer. using a sharp object, I feel like I can almost scrap it off.
This is different from regular paint, where I feel I would scrap off
the stucco instead of the paint if I tried. (My wife has put a metal
patio chair next to the wall, and it actually came in touch with the
wall when we were using it. Afterward I noticed where the back of the
chair touched the wall, the paint was damaged a tiny bit. I didn't
actually try to see if I can scrap it off with a screw driver or
I called them, they said they'll come out and take a look. Most likely
need to sand it off and re-paint...
I cut one of the bubbles open, it was water inside. I am going to try
to see how much paint I can peel off tonight from this area.. This
would give me some indication of how good it is sticking to the wall.
Your descriptions get confusing - does the paint rub off by hand? It
would be normal for paint to come off if scratched with something sharp!
If the blisters have water in them now, it MAY BE possible that
moisture was driven through the paint film by high wind, now expands
with heat of day. IF the surface was wet when it was painted - you
think "maybe" they painted day of pressure washing? - seems the blisters
should have appeared before now.
Depending on how large an area is involved, it might be adviseable to
poke each with a sharp point to allow water to escape. As said before,
if the rest of the paint film is intact, the blisters will shrink and
You don't SAND stucco to remove loose paint - pressure washing
(experienced, using correct pressure) is the method.
Whether the storm could have driven water through the paint film would
be a good question to ask of the paint co. before you discuss any
corrective measures with the painter. Latex paint is commonly used on
masonry because it allows more moisture to move than does alkyd paint,
and masonry always has some moisture in it.
Priming/painting should not have begun until 3 days of dry weather. It
should not have been painted in the hot sun - painting should proceed
around a building so to avoid hot sun.
Ok, the heavy rain hit on Tue. The weather was cool during the day.
Very windy. I noticed the bubble after the rain finally stopped around
5pm (it has been raining for 12+ hours). Your explanation seems to
make sense. If the film for that wall is not as thick as it should be,
then perhaps the rain has driven moisture through it? (is it
Wed was a sort of sunny. After I got home last night I can still see
the bubble. Perhaps it was a bit smaller but I didn't look at it too
This morning (Thu), I was ready to cut open those bubbles because I
don't want to wait to hear from my painter. I went out side, and they
were all gone. The wall looks completely normal now. Damn it. I can't
even seem to find the one I cut open! I think the water must've
Yesterday I called Kelly Moore asking them about the bubble, and they
told me to call their expert line. Spoke to someone there, and he said
that I need to find out where water is getting through, and fix that.
I asked him whether elastomeric paint is the wrong paint for stucco,
and he said it can be used for stucco (ie, not the wrong paint), and
claimed he sells thousands of gallons of it for stucco everyday. I
asked him about stucco breathing, he claims it allows breathing (but
not when water is somehow getting behind I guess).. So talking to him
made me feel a tiny bit better, that I didn't mess up my house by
using the wrong kind of paint.
No. That wall was the last thing they painted, definitely not the same
day power washed. It looked perfectly normal, with no blisting or
chipping paint, until the rain hit.
That's exactly what happened before I get a chance to cut them open...
Now that the bubble have disappeared. Will simply repainting it be
enough? Will power wash get rid of the paint where the bubble was?
What's the proper way for power washing?
Thanks to everyone who have been helping out!
A moisture meter needs 2 metal probes to stick in what you are
measuring, I didnt see any so check. You now indicate it didnt scrape
off? if water is behind bubble you have a building issue not a
aplication issue. Water behind the bubble happened recently from a
defect of your home, wherever its comming in you need to find and fix
the issue, a moisture meter sure will help alot in finding leaks. ,
ive used one for years, its the best thing you could get but it needs
probes that penetrate wood at least 1/4".
replying to ransley, Real Painter wrote:
This is completely untrue. I am a contractor not a homeowner who knows nothing.
Your house is 50 years old and the stucco is old. There could be many reasons as
to why your stucco is bubbling. The most obvious of which is the fact that water
got in your stucco. Chances are only a scratch coat was applied to your building
and it is now becoming old and needs to be scraped really well and a new coat of
Stucco needs to be applied. If stucco needed to breathe then commercial painters
would never apply a Sheen to stucco which they do all the time and no problems
occur. The reality is that stucco is not supposed to be painted.
Nobody can answer those questions without knowing the specifics of what
kind of surface (stucco on what), the product (not just the brand), the
preparation, the conditions when the paint was applied, the old finish,
etc. Do you not have some left-over paint so you can find the exact
product? If not, call the painter. It should have been stated on the
contract when you hired the contractor.
For starters, call the contractor and advise him of the problems, esp.
the fact that the paint rubbed off. Follow up by writing to him,
stating clearly the problems occurring and when they appeared.
Kelly Moore has a website with some general descriptions of their
products and intended uses, here:
If the paint rubs off, which you did not state in your original post, it
is highly likely that the surface was chalky and/or mildewy when the
paint was applied. If moisture was the original problem, you should
have seen blistering sooner, it seems.
There is a "contact us" link on the page for KM. Let us know how it goes.
Yep, you have trapped moisture. You're only seeing it on the Southern
side because that wall heats up more in the sun, and the water is
either expanding or creating water vapor - probably the latter.
First thing to do is to bleed 'er. Popping them with a pin will most
likely just put you back at square one with the bubbles after you
repaint. Slice off the bubbles with a razor blade.
The wall has to dry out before you can repaint. That's a tough one
in the rainy season. If you don't have too much area to deal with,
and too many bubbles, you could use a heat gun or hair dryer to heat
up the ex-bubble locations.
Repaint when all is dry. Spot prime if the manufacture recommends
it. Contact the manufacturer in any event and see if they have a
Note that some answers here are based on stucco over cement block
(common in Florida) and some are based on a wood frame building with
stucco, typically over a wood substrate. Answers for one are not
necessarily appropriate for the other.
And in the second case you could have the 'modern' EFIS stucco. I that
case, IMHO, you need an expert opinion. There are horror stories
I assume you have conventional stucco and a wood frame house.
Ask a stucco contractor what should be used and if "elastomeric paint"
is a good idea. Or you could ask a *good* paint store.
I agree that it is best not to paint stucco. I would rather "redash",
which is a thin layer of stucco with pigment. That keeps the surface a
low maintenance stucco finish. Painting turns the surface into a much
higher maintenance painted surface.
I have always been told that if paint is used it must "breathe". This is
particularly true in older houses that do not have the effective vapor
barriers used in new construction. The vapor that escapes the house into
the wall must easily escape through the stucco. If trapped by paint you
can have headaches like peeling paint and rusting metal lath.
I understand elastomeric as a paint that does not breathe.
To get all the paint off of stucco sandblasting is commonly used.
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