Designing Kitchens and Bathrooms - Tiling Bathtub Box (Plywood)

I built a box onto the side of my tub with intentions on tiling it. Made of plywood. Now, everyone tells me tile will not stick to plywood, especially in a humid place such as a bath. Is this true? Rebuild with cement board is not an option. If true, is there anything I can apply to the plywood to help mortar adhesion?

Thanks in advance.

The trouble with plywood is that it absorbs the moisture from the environment and flexes over time - making your thinset crack and grout lines do the same - or at worst, causing the tile to pop off.... If there is any way at all to put a 1/4inch backerboard on the plywood - do so..... That extra 1/4inch is pretty easy to work with when setting your tile.

Hi,

What kind of plywood did you use for your enclosure? How many layers of what thickness?

Just RedGard all the junctures. Tape the corners (in and out) with mesh tape and embed the tape in about 3 or 4 coats of RedGard. Watch for pinholes.

Doesn't sound like you intend to change anything anyway so waterproof it and go for it.

So.....are the walls plywood also?:wall:

Now, everyone tells me tile will not stick to plywood, especially in a humid place such as a bath.
True, tile does not stick well to plywood even in the best of conditions.

If you really can't rebuild this, I suggest fibreglassing the plywood and gluing the tiles, possibly with more resin. A ton of staples in the plywood provide grips for the fibreglass resin - this is how we do boat hulls.

If your bathroom is well vented, the box will probably last longer if it has some opening so moisture does not stay trapped inside it.

If you really can't rebuild this, I suggest fibreglassing the plywood and gluing the tiles, possibly with more resin. A ton of staples in the plywood provide grips for the fibreglass resin - this is how we do boat hulls.

Your kidding right?:thinker:

Rebuild with cement board is not an option.

Why not?:)

...tile does not stick well to plywood even in the best of conditions.

Not at all true. Tile can be applied to some plywoods most effectively, BUT, there are specific methods to be employed that insure a long lasting job.:D

Your kidding right?
About the box or the boats, no. (?) We fibreglass decks and areas around pools outside too, similar situation, only I rate this bathroom tile box worth a greater investment than outdoor construction.
Not at all true. Tile can be applied to some plywoods most effectively...
Well, yeah... there are many ifs and buts. And at some stage of precaution we're not really applying tile to plywood, rather applying tile to thinset, which is applied to something else, and that to something else... the plywood is under there somewhere. :blah:

About the box or the boats, no. (?) We fibreglass decks and areas around pools outside too, similar situation, only I rate this bathroom tile box worth a greater investment than outdoor construction

There are different ways to waterproof substrates for tile. I must admit that I have never heard of this one. I dont think fiberglass would be a good substrate for tile either. An easier more conventional way would simply be to use one of the paint/trowel on membranes like laticrete 9235. Redgard over plywood states "dry areas for crack isolation only" so its probably not a good choice here.:)

Wow! It's like the OK Corral here...all our sharpshooters have an opinion.:)

Trkshot, could you possibly upload a picture, either on Picasa or photobucket, post the link here and let us have a look at it?

Thanks!

I must admit that I have never heard of this one. I dont think fiberglass would be a good substrate for tile either.
The first statement, well, I've never heard of fibreglass as tile substrate either. As for second, here's my reasoning: We know fibreglass just rocks for laying a tough and 100% watertight shell over troublesome stuff, like plywood, and problem joints. We trust it to severe conditions. It could do the job alone without the tile... as in fibreglass shower stalls, right? I also know (have tried it) that tile bonds crazy strong to polyester resin. Add it up. :)

This seems like a reasonable investment of effort to make absolutely sure the project can't fail.

I do like fibreglass. ;) Enough said.