Can a mosaic over styrofoam last outdoors if properly grouted and sealed?

Answer 1

A mosaic over styrofoam can indeed last outdoors but here is how I would recommend preparing your base first. I would wrap the styrofoam in strips of fiberglass mesh covered with a "slurry" of either mortar or cement. This is approximately what products like Wedi board or Easy Board underlayment are: foam core sandwiched between layers of fiberglass mesh and mortar. I would not recommend using a styrofoam glue with ceramic or glass tile for outdoor use because it is more likely to crack with changes in temperature. This is not the case with mortar, which is polymer or acrylic latex modified for maximum flexibility and strength.
Once you have completely wrapped your styrofoam and let it dry, you can then mosaic on top of that layer, once again using appropriate mosaic tile (porcelain, bone china, stoneware, glass or high fired ceramic) and thin set mortar. Use sanded grout that is also polymer or acrylic modified.
My mosaic work is made to withstand Chicago winters and I have quite a bit of experience with this. If you have any more questions, don't hesitate.

BTW, fiberglass mesh is available from Home Depot in the form of screen door mesh.

Answer 2

I've installed lots of tile and really the only time you can't use the shower is between the time you lay the tile and you grout it. after you grout the shower (and rinse, rinse, rinse, rinse & rinse some more.) 24 Hours is plenty of time to wait to seal it. But if you are thinking (and it sounds like it) that the sealer's job is to make it water proof, it isn't. Sealer just makes cleaning the grout easier and keeps the grout from absorbing stains, soap scum etc.. You really could go with out sealing, but best practices say seal. After all how many people do you know that even bother to reseal a shower, ever. The grout itself is water tight. So unless you're planning to shower with red dye #2, I'd turn off the garden hose and start showering.

Answer 3

YES. Most outdoor store signs are painted Styrofoam. Styrofoam is water proof, but will turn yellow and break apart in sunlight. That is why outdoor letter signs are kept painted. The problem will be getting the tile to stick the foam. You can put stucco on the foam and then tile the stucco. Its an interesting idea. May try it for a garden art project. Thanks for the idea.

Answer 4

Yes. Tiles rely on a solid unbending base.It would be better to cover the foam with a solid surface before applying tile. Be sure to use grout recommended for exterior use and a quality sealer.

Answer 5

all the roccoco details in las vegas casinos are (construction grade) styrofoam shapes.

a special stucco covering is sprayed directly onto the surface.