Tiling a curved, vertical surface
I’m hoping that my knowledgeable colleagues from across the country can advise me on the best method for creating a curved substrate for tile.
To make it simple for you, I have lots of experience setting tile. I’m not looking for how to set the tile. What I am looking for is advise on the best technique for creating the surface to adhere the tile to.
Here’s what I’ve got: I’m building a hot-tub/sauna house and the floors and walls in the hot-tub room are to be tile. I have built a couple of steps to get into the hot-tub and also a bench. The steps are in one corner, the lower step is a 30″ convex radius. The top step is a 20″ convex radius. Adjacent to the lower step is a bench that fits into another corner. The inside facing of the bench is a concave radius of 20″.
I have framed the steps & bench with 2X materials and have plywood on the top surfaces.
Here’s my question: what is the best technique for covering the face of the steps & bench to prepare for tile.
Obviously, (at least to me), it would be best to use a concrete/mortar substrate. Never having done a curved, vertical surface, let alone a compound curve, I could use some help as I don’t know how to do that. If that’s not the best method, then I would like to learn what is.
I need the basics: what do I put on the studding to get the mud to stay there & maintain a nice curve & plumb surface, do I need to be concerned with a moisture barrier, what are the best materials-(including the type of mud to use), etc, etc.?
(Before any of you chastise me for taking on a job that I don’t know how to do, let me put your mind at ease: this hot-tub house is for me. (I desperately need to warm up/soak this tired, old body after 30+ years of carpentering!)
Thanks in advance for any & all help.
Also, if any of you have any tricks for setting the tile on the curves, I’m all ears. I plan on using the largest width tile I can while still maintaining the smoothness of the curve.
Don't worry about taking on a job that you don't know how to do. We do it all the time for paying customers. Not because we want to but because we can't find anyone with the required expertise in our area.
I've never built a curved tile substrate but I watched our tilesetter do one. He had a plywood curve at the top and bottom of the wall with studs set in from the curve 3/8". He fasten felt paper and wire lath to the studs and applied a mud bed to this lath using the plywood to screed the mud. His studs were placed fairly close together. He only used one batch of mud and it took quite a while. I would probably use a scratch coat but I am no tilesetter.
Good luck and maybe we can get a true expert to respond.
You could try posting your question at the John Bridge Tile Forum. Always a mud man or two hanging around there to answer questions...
...get an up-north attitude...
we did one last year with as many curves you are describing but in granite. If the sucky search engine worked you could find it in the gallery somewhere. No mud. Hardies villaboard onto a ply base then glue to the villaboard. ( you may not have villaboard in the states, check hardies site ) Both cuves required a lot of cutting and mitreing
You can bend Durarock . I don't know how tight you can go but I bent some to a seven foot radii. lay it over a wood form and gradually move weight out to the ends. I used a 5# bag of grout maybe it was 10#.
I kerfed Durock and used thinset as a scratch coat to round out the folds from the kerfs. Lots of framing behind so no big unsupported areas.