QUESTION

How do I install Mosaic Tiles to be Freeze Thaw Proof - I am doing a tile mosaic on a circular concrete base about two inches thick. It will be used as a table top, but will be about a hundred pounds, and difficult to move around. I would like to take precautions so that it will resist the freezing winters in the northeast. Is there anything you may be able to recommend insofar as special mortar or anything to insure it will be weather proof?

ANSWER

ANSWER - First you need to verify that your mosaic is frost proof/freeze thaw stable.  If it is porcelain or vitreous clay tile it is possibly frost proof.  If it is a stone mosaic then it may or may not be frost proof.  The more dense/less porosity the stone the more likely it will be frost proof. If it is a glass mosaic it in itself is normally frost proof, but it needs be properly bonded.

As far as what to use to bond the mosaic to the concrete base it depends.  You can use a latex or polymer modified thin-set mortar that is recommended for freeze thaw applications.  You can use an epoxy adhesive for tile and that would work since it doesn't absorb moisture and has great bond strength.

It is critical that the concrete base is properly scarified to open its pores to ensure a good attachment prior to installation.  I would further recommend applying a liquid applied tile waterproof membrane first and then bond the mosaic to the membrane.  That will help keep the moisture out of the concrete and provide some protection from getting efflorescence from the concrete migrating to the surface of the tile.  For a list of tile installation product manufacturers with links to their websites go to our website at www.CTaSC.com to Resources under Expert Answers.  good luck.