#Wooden mosaic shapes crack#

Brands of foam-core backer board include Durock and KerdiBoard. This hard expanded polystyrene board is water resistant and can be cut quickly by scoring with a box cutter and snapping.

One option for outdoor mosaic table tops is to use a piece of foam-core board such as used to fabricate bathroom surfaces. This image stolen shamelessly by Evil Joe from the Schluter website. It can be cut quickly and easily with an ordinary circular saw or table saw. Custom Mosaic Table Top Backers Kerdi Board Tile Backer by Schluter is hard expanded polystyrene. Most of the work is buffing off the excess so that the surfaces are slippery. Silicone-based gout sealers are wipe-on-wipe-off and easy to apply. Seal your finished outdoor mosaic with a tile and grout sealer and reseal it each fall. If you have a wooden table that you want to mosaic for outdoors, then attach a piece of 1/4-inch concrete backer board over the top of the wood and mosaic on that. Once grout has hairline cracks, moisture can penetrate underneath, and then there isnвЂ™t any hope for the mosaic lasting after that happens.

#Wooden mosaic shapes crack#

Humidity in outdoor air can cause plywood to swell, contract, and warp, and even if the displacement is too small to be noticed, it can still cause grout to crack and tiles to pop off. Plywood is never an acceptable backer for outdoor mosaic table tops. Artist Risa Puno recently completed her interactive mosaic sculpture Common Ground for Rufus King Park in Jamaica Queens, NYC, and the project is a great example for discussing materials and methods for mosaic table tops.