Your shopping cart is empty.

Waterproofed stucco walls in bathroom - anyone done this?

October 10, 2016
last modified: October 10, 2016

One idea we are considering for our guest bath is using waterproofed stucco or venetian plaster (smooth) walls. Has anyone here done something like this? Any thoughts or caveats (cracking, etc) on this application? What's the best way to achieve this look?

Comments (12)

  • MongoCT

    Never done stucco, but yes on venetian plaster.

    VP, there should be no cracking or structural issues. With good ventilation you should have no negative issues whatsoever.

    I've never had negative feedback.

    Pipdog thanked MongoCT
  • homepro01


    What substrate would you use for the VP in a bathroom? Also, how would you waterproof?


  • rockybird

    Pipdog this is great! THanks for posting it. I am going to ask my contractor about the feasilbility of this for my master bathroom.

  • MongoCT

    I've only done a few, on floated mud walls.

    I have heard of it being used over foam-core panels like Wedi. Schluter was supposedly working on an approved application over Kerdi Board, but I never looked into where (if anywhere at all) they went with that.

    A large concern for me would be any flexing of the substrate.

    For remodeling, if it was used over a membraned foam board, it should adhere directly to the fleece, or you may prefer to apply a scratch coat of mortar, or perhaps even a scratch coat of thinset for the membrane first. Just something to give the VP a bit of rough texture to grab a gold of. I like the skim coat of thinset as well to cover any seams where the membrane overlaps itself. The more uniform your substrate, the more control you have over how the final product looks.

    I've never looked in to doing it over a cured liquid membrane like RedGard or Hydroban liquid. I'm thinking (again, no proof) that because of how it's applied it might go on better with a scratch coat of thinset/mortar over the liquid membrane before applying the VP. Skim coating those with thinset would also mask their colors from shadowing through the color fo your plaster.

    I am NOT a plasterer! So certainly do some research and get in touch with the tech departments of whichever product you plan on using.

    For sealing, I'd recommend sealing a stucco. For VP, it depends. Again, I'd follow the manufacturer's advice. There's usually a soap/oil/stone treatment, depending on how authentic you want to be. I didn't seal some of the ones I did. I believe the homeowners were going to seal afterwards.

    Pipdog thanked MongoCT
  • homepro01

    Thanks Mongo! This is good information. Maybe an interesting alternative over tile. I wonder how easy the walls are to clean with soap scum.

    Pipdog thanked homepro01
  • Pipdog

    Thanks, Mongo for the useful information. I'm meeting with our GC on Friday to discuss what might work best. I'm not exactly sure if we're going to use stucco or plaster, but I will share what we decide to use and how things turn out.

  • rantontoo

    In the late 50s and 60s, plasterers used a product to supposedly waterproof plaster. An additive was added to the plaster mix and a final topcoat of another product was sprayed on. My dad, plasterer by trade, did this to the walls of our alcove bathrtub so a shower could be added later. He never added the shower because of his concerns over possible water damage to the walls. Hopefully, waterproofing plaster has come a long way! Good luck!

  • rockybird

    I called the top plastering company in the state - they have an excellent reputation and do multi million dollar homes - who told me they did one of these showers once. When I pressed them, they said it was too much work, they will not do it again, and they dont recommend it for homeowners. I discussed it with the contractor and we are both worried it might not hold up since we dont know an experienced contractor. If we had an experienced contractor here, I would definitely Consider it. I also spoke to the ID who has designed them before. She showed me a pic of a large shower done in plaster with tile floor she had recently done. It was beautiful but more mottled and rough - looked great in the adobe style home. She said she didnt know how it was holding up. She is not recommending it for me - so back to Heath tile! If you can find a reliable contractor, Pipdog, please post about how it goes. I wish I could do a shower like this!

    Pipdog thanked rockybird
  • PRO
    Joseph Corlett, LLC

    If they can successfully put stucco on the exterior of a building in areas with hail and freeze thaw cycles, it certainly seems reasonable that it would withstand a little shower sprinkle on occasion without failure.

    Pipdog thanked Joseph Corlett, LLC
  • Pipdog

    thanks for the info, rockybird. I'll let you know what we find out. We have tile picked out as backup (large format tile for the wall), but I'd love to make this happen if it's not prohibitively expensive. I also found this bathroom but did some poking around about Tadelakt and it's very pricey, and there aren't very many artisans that do it. Plus, I'm not sure the mottled/Moroccan look is what we're going for. We want more along the lines of the very sleek look of the first inspiration photo.

  • rockybird

    Yes - please keep me updated. I haven't ordered the til yet, but will within a week. I dont know that it has to look mottled. If I could be guaranteed the look below, I would do it in a heartbeat. This is a bathroom I've liked for a couple years and I just now noticed it's not tile, but plaster!

    wood block residence · More Info

  • MongoCT

    You can get that first photo look fairly easily. Just have all your product tinted at the same time so you have color uniformity from layer to layer.

    Going three layers instead of two will also help even out any variations in color. The standard application is to apply it with metal trowels. You can do that, but to minimize color variation, once all coats are on you can go over it with a sponge float. The sponge flota will even out the entire surface, with regards to both texture and color.

    It's not an overly difficult product to apply. You could probably take a class and go DIY if you wanted the satisfaction of knowing your did it yourself. In general, it's a 2-day process to apply the two or three coats, then another day to soap/stone the surface. Stoning the surface, THAT was the tedious part. Wax on, wax off, times a thousand.

    I called Schluter tech support, they recommended skim coating the Kerdi with thinset. Let it cure. Then apply the plaster over the thinset. I'd add in if you want a white finish as in your first photo, use white thinset instead of gray over the Kerdi. Same as in my previous post. The skim coat will get mask the Kerdi orange color as well as get rid of thickness differentials at the seams. Thinset is a lot less expensive than the plaster/clay material.

Need help with an existing Houzz order? Call 1-800-368-4268 (Mon-Sun).