Anyone ever apply a waterproofing to a large stucco wall to prevent wind driven rain from penetrating it?

Buddy of mine is a higher end home builder and had an issue with water penetrating stucco at one of his homes. When trying to fix the problem, every stucco contractor he talked to had a different opinion on the property way to water proof. Probably doesn't help much... But long story short, it's not an easy answer and I'll never put stucco on a house in Houston or similar climate.

I hate to be the bearer of bad news but the only way to truly fix water intrusion through stucco is to remove the stucco and redo the waterproofing system behind it.

http://mattrisinger.com/stucco-failures-right/

Stucco sucks. But best practice is for a layer of waterproofing be installed before the stucco, along with counterflashing.

Thy make elastomeric paint used for stucco for this reason. It goes on thicker, fills in pores, and has more flexibility where I it can help full hairline cracks and handle a little movement.

If you have larger cracks, you need to fill those first with some kind of sanded polyurethane sealant. If it is a really heavy, rough stucco, it is uncommon, but there are block filler type coatings typically used on CMU that can help on stucco under an elastomeric paint.

Thanks for all the feedback. My problem is not so bad that I am considering rebuilding the wall. The stucco looks great and I only have a problem a few times a year with wind driven rain after a strong cold front. I used something like this on a brick wall on another house that had the same problem and will try again.

https://www.concretesealersusa.com/ps102-siliconate-multi-surface-rough-wb-penetrating-sealer-1-gal/

if you are having the problem a "few times a year" then the waterproofing you are considering is just a band aid.

You really should consider rebuilding the wall.

you probably have issues everytime it rains, but they are only bad enough for you to see its an issue a few times a year... most likely everything behind the stucco is just saturated and will have to be replaced.

Foamcows said:

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you probably have issues everytime it rains, but they are only bad enough for you to see its an issue a few times a year... most likely everything behind the stucco is just saturated and will have to be replaced.

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this.

OP didnt mention exactly how they observe this water issue either...would be interesting to know

I cut a monitoring hole about a foot square right at the floor level where I found mushy MDF baseboard last winter when it seemed to rain the whole month of December. My wife wants it closed because its in the laundry room. It only gets wet in the winter when we have a strong north wind driving rain through the stucco. Its powdery dry right now.
Since it doesn't seem to rain around here any more (rural Washington County) I've put off worrying about it.
At that particular spot the rain does not drain like it is supposed to. But the wall is about 60 ft long and two stories tall. There is no wet MDF baseboard anywhere else. I have thoroughly caulked all cracks, seams and anywhere else I thought water might be entering the wall. I have a brand new standing seam roof.
The wall has been there since 2005. I bought the house about a year ago.
I guess I could remove the stucco from the whole wall and build it correctly.
I've called several contractors who seem to know something about stucco walls but so far nobody is interested enough to come have a look. If one of them were to propose replacing the wall I would probably listen. But in the meantime the band aid approach seems worth a try.

On the positive side, at least it's not EIFS.

Call my companies stucco/EIFS division - http://www.parexusa.com/. Ask for the local rep or tech rep. They might be able to help you out.

What's wrong with EIFS.

Problem with EIFS is once water gets behind it, it can never leave.

That white powder is most likely glue that has seeped out of your mdf when it was saturated and then later dried.

The only real way to test for issues is to get a meter that can measure moisture levels. I would start with testing at the corners along the base of any window frame.

After having over 30k of stucco repair in a previous home and seeing almost every stucco house on our block have eventual repairs, you soon realize that the issue with stucco is you can have an issue but by the time it's so bad that you can actually see water damage or any other symptoms, it's too late.

Well... hopefully my house is sealed up good.

Most eifs these days is drainable, i.e. there is a dimpled drainage mat that allows air and bulk water to move out from behind it. Old eifs was placed directly against substrate and would trap moisture, thus rotting .

you can also try using a product like GAF Masonex. It is a clear masonry sealer. Pretty easy to apply and works well.

https://www.gaf.com/en-us/roofing-products/commercial-roofing-products/non-roofing-coatings/wall-coatings/masonex-clear-masonry-sealer

Yes there are quite a few products like this on the market. I used something similar on a brick wall once. Thanks for the feedback.