Hello - My first post to the forum ... My wife & I recently bought a Rastra block house built in 2004 in Tucson. The cementitious stucco is applied directly to the Rastra block and then painted (no idea if elastomeric paint was used, but know that last coat was acrylic latex paint). We knew the garage leaked at time of purchase, just not how much. And now the master bath is leaking as well as the master closet (we think). All leaks are at the floor level with no interior wall damage. We have confidently determined the problem is with the cracked stucco exterior walls. These walls have no windows or doors, it is the actual wall that is leaking. We can see that the walls have been patched many times - there are smooth patches of stucco where the patch was not textured, and there are "veins" where stucco cracks were patched (badly). If I shoot a water hose for about 5 minutes on some of these cracks I can reproduce the leak. The leaks only happen with wind-driven rain. We have had multiple (more than 7) stucco contractors and 3 painters. All the stucco contractors push synthetic stucco for the entire exterior (very expensive). Painters push Seal Krete then skim coat with cementitious stucco and paint with elastomeric paint. I have read horror stories that if synthetic stucco systems are not installed properly or if elastomeric paint is not applied properly both can cause more damage than good. Can anyone please offer their opinion on what approach to do? We would strongly prefer to just do the 2 walls that have the known leaks and wait for multiple rains to verify the leaks are fixed before doing a whole-house fix. We are leaning between a STO solution of: STO Gold Coat water resistive barrier/STO adhesive/primer, fiber netting, STO synthetic stucco OR a paint solution of Sherwin Williams Loxon clear sealer, Loxon XP waterproofing, and Sherwin Williams Duration paint. Are either of these wise approaches? Thank you all.

I have a similar problem on my house, built in 2011 and purchased inexpensively due to the leaks. My leaks are more front and center because they are all on a wall where the roof drains.

Disclaimer - I'm not a pro by any means. I've just spent my life buying houses that the git'er done flavor of contractors made a mess of and figuring out the correct way to fix their mistakes. Read a lot about stucco over various surfaces, and I think I now understand it pretty well, but a really good stucco guy is definitely going to know better than I do.

I would avoid trying to get a painter to fix a stucco problem I would also avoid cementitious stucco on an ICF wall - even skim coats of it are heavy and you need a plan to hold up that weight. ICF's are great in many respects, but holding up a heavy wall treatment are not something they are designed to do as well as a framed wall with foam sheets. It may be possible to do a cementitious skim coat with a proper bonding agent application first, I don't know, but I kinda doubt it.

The question is then whether your stucco contractors are giving you good advice. How consistent is the advice between the 7 you've talked to? If they are all saying the same thing, then probably it's good. I would watch out for contractors who view one foam wall as the same as any other, what is under the foam is important because it changes your available options. If there's a big variety of methods suggested, then you need to use your own judgement.

Your synthetic stucco solution sounds about like what I plan to do on my house. Only difference is that I'm considering some expansion joints as well. One guy I talked to said they use joints on synthetic coat walls when it's more than 50' or so. The failures I see on my place are consistent with lack of a joint on the large runs, but also complicated by what are clearly adhesion problems.

I would also suggest going as smooth as possible with the finish, even with synthetic products. Really sandy, rough surfaces tend to hold water and soak it up. You want the rain to sheet right off the wall as quickly as possible.

The last thing I would say is to make sure you have drainage away from the wall. The problems could have started due to ponding at the base and caused continued failures from there. Good drainage never hurts (especially in AZ where summer rains can give you huge amounts of water very suddenly!) and the time to fix any drainage is while fixing the stucco or right afterwards.