Started in on mosaic work this winter

So far I have done a small table top, a cylindrical cement birdhouse that I learned how to make at Riana's Garden workshop, and 4 pictures on the backs of 13' porcelain floor tiles. Great winter work! I need to find a source of tiles that are frostproof though. I thought all porcelain tiles were in this category, but recently found out differently.
I will post pics as soon as my photo skills are up to date.
Sharon