The best grout gap for mosaic artwork depends on whether or not the mosaic will be outdoors or in a potentially wet location such as a backsplash.
When Do You Need A Grout Gap?
If the mosaic might get wet or exposed to humid air, you can’t have the tiles touch each other. You need a gap for the grout to fit into to seal out moisture.
Tiles that touch can never touch close enough to seal out moisture.
If the mosaic is a small indoor icon or plaque, you don’t have to worry about sealing out moisture, and so you can fit the tiles tightly together and skip grouting.
TIP: You might want to grout anyway to fill in any small incidental gaps left by imperfectly shaped tesserae, especially if your mosaic is a “dry” tabletop or architectural surface. (If those surfaces are in the kitchen or bathroom, you should consider them “wet” and use a grout gap.)
Smaller Gaps Preferred
Smaller gaps are preferred because they make grouting easier, and they minimize the color impact of grouting.
A grout gap only needs to be large enough to ensure that grout can fill the gap all the way to the bottom and not just a smear across the top and hide a void underneath.
Ivana and Natalija have made some Halloween-themed mosaic coasters, and Natalija even put together a Halloween Mosaic Coaster Kit. The kit comes with the tile and materials needed, but it doesn’t come with a pattern.
As always, we encourage people to make their own designs, but we do have instructions for copying images to make a mosaic pattern.
At Mosaic Art Supply, we have always tried to promote contemporary mosaic as a fine art and help people of every skill level create original work instead of selling overpriced craft kits for making cliche designs. This may have hurt us some financially, but I have never regretted taking the high moral ground. After all, if I wanted to help people mass produce junk, I could have remained an engineer in the corporate world.
One of the things that I have found particularly rewarding is seeing great art made by ordinary people with no formal training in art. I have also enjoyed seeing the range of styles that professional artists have been able to execute in mosaic, proving that the medium is as versatile as oil painting, perhaps even more so because of the found object and textural elements that mosaic can incorporate.
Recently one of my employees showed me the work of artist Yulia Hanansen, and I was intrigued for several reasons, and not merely because of the stylistic range of her work, which is impressive in itself.
It would be difficult for me to say which piece is my favorite, but I particularly like the kitchen backsplash with the paleolithic cave painting images from the epic period of human prehistory known as “The Great Hunt.” I like how its cool cyan color scheme complements the warm wood cabinets. It is not only an interesting and original mosaic. It is also a well-integrated part of the room’s interior design.
Vitreous glass tile has a lot fewer surface pits than it did a few decades ago, but it still has some, at least in most brands. Grout can sometimes lodge in these superficial pits if you don’t adequately sponge and haze the mosaic after grouting, and many novices find this problem particularly distressing.
The good news is that the problem can be fixed easily, and it can be avoided for the most part by correctly sponging and hazing the mosaic during the grouting process.
Avoiding The Problem
You do NOT need to find vitreous without pits to avoid the problem of pit staining.
Keep in mind that the same vitreous tile is used as an architectural covering for thousands of square feet at a time, and so common sense tells you that there has to be a way to get grout out of pits without a large amount of labor.
I feel the need to stress that point because I receive emails from beginning mosaic artists who are desperately searching for vitreous glass tile that is perfectly smooth without the occasional pit: You do NOT need to find perfectly smooth tile.
Artist Morgan Halford recently emailed us some pictures of some mosaic Christmas-tree ornaments she made with the spherical bases we sell, and I wanted to show them off for two reasons. First, the tiling is tightly executed in terms of grout gap and pattern, and the designs she used are interesting and eye catching.
Adam and his sister Teneisha of Toni Craft made a video of their micro-mosaic jewelry project using deep-bezel jewelry findings and stained glass, which we also sell as assortments called Mosaic Art Glass, because the colors were selected to be fairly opaque when mounted on an opaque surface.
Stained Glass or Recycled Glass Tile?
Instead of stained glass, I prefer to cut small pieces from recycled glass mosaic tile, which cuts much more cleanly with less waste because it is made by fusing glass powder, which results in a more homogeneous composition. Swirled stained glass might generate more waste and odd sharp slivers because it breaks along the veins of the swirls, but there are reasons to use it in spite of the scrap. For starters, stained glass is more sparkling than recycled glass tile because it is semi-translucent AND it has interesting variegated colors. Besides, for micro-mosaics, you only need a tiny amount of material, and so waste isn’t a problem, especially if you save it for glass fusing. Continue reading →
Putting a mosaic on a metal mailbox is problematic because either the metal is painted and you risk the mosaic not adhering well, or because the the metal is bare, and then the thinset mortar is likely to oxidize (rust) the metal over the years.
Fortunately, there is an alternative that makes more sense for mosaic, and that is to build a column of field stones or bricks or cinder blocks and then plaster over that with mortar and put the mosaic on the smoothed surface. In this design, the mailbox can be mounted on top of the column or built into a niche in the column near the top.
Artist Linda Robertson recently emailed me some pictures of her mosaic mailbox, and it is a good example of an alternative mosaic mailbox that avoids putting the mosaic on the metal itself. Continue reading →
Outdoor mosaics must be made on concrete or stone or masonry, but that doesn’t mean you have to pour a concrete slab or do some other form of heavy construction.
Flagstones (flat paving stones) and concrete stepping stones are readily available at building material stores and lawn and garden centers. The flagstones are great if you want a natural irregular shapes, and the molded stepping stones are great for square and rectangular shapes.