An architectural mosaic can cut someone if sharp edges are left exposed or crush someone if it’s not mounted securely. Even a small mosaic plaque is significantly heavier than a painting or photograph of the same size and should not be hung with light gauge wire or fasteners.
Would You Glue Razor Blades To Your Shower Wall?
Use Smaller Grout Gaps To Reduce Cuts
Tighter (smaller) grout gaps helps reduce the potential for cuts. It’s intrinsically more difficult to cut yourself the closer the pieces are together because the closer they are, they less flesh that can be pressed between them.
However, there must be a grout gap large enough to get some grout into during the process of rubbing the wet grout into the cracks. Grout (and thus a gap big enough to be able to press wet concrete into) is needed to seal out water. That is one of the big ironies of mosaic: You can make your mosaic significantly more vulnerable to water damage by mounting the tiles so closely that they touch. Wet concrete might find it difficult to fit into a hairline crack, but water won’t have any problem.
Grout Cannot Hide SIns (Forever)
Grout erodes over time, particularly in locations with lots of water and traffic, such as the bathroom floor and shower stall. When the grout erodes, it re-exposes the sharp edges. Don’t use grout to hide safety problems.
Repair Damaged Mosaics
Repair damaged mosaics by prying off broken tiles or smoothing with a marble file.
Mount Mosaics Securely
The most secure mounting for a mosaic mural is a stone, concrete or masonry wall. However it is possible to mount a mosaic mural on a wood-framed wall provided you review the wall with a carpenter to make sure it’s structure can support the weight.
Smaller mosaics may be mounted using multistranded stainless-steel picture wire with construction-sized wood screws, but install a redundant wire as a back up. Use multiple fasteners in the wood and stagger their locations so as not to split the wood.
Larger murals should use steel mounting clamps or mounting trays. The fasteners should be of structural size and not finishing or cabinet nails. Put fasteners in studs and review your mounting scheme with your carpenter when you review the wall with them. Weights of large murals can be calculated from area multiplied by unit weight, which can be summed from component materials if not actually weighed on a scale.
Make sure you have a carpenter look at the wall to see if it can bear the load.