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.No Plywood Backers Outdoors
Plywood is never an acceptable backer for outdoor mosaic table tops.
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. Once grout has hairline cracks, moisture can penetrate underneath, and then there isn’t any hope for the mosaic lasting after that happens.
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.
Seal your finished outdoor mosaic with a tile and grout sealer and reseal it each fall. Silicone-based gout sealers are wipe-on-wipe-off and easy to apply. Most of the work is buffing off the excess so that the surfaces are slippery.
Inspiring mosaic table tops with abstract geometric patterns were recently created by artist Risa Puno as part of her public art project Common Ground, an interactive sculpture designed to bring people closer together physically.
The concept of Risa’s sculpture plays on the metaphor of multiculturalism as mosaic, but instead of the folk or children’s artwork usually associated with that theme , there are cleaner abstract designs with color choices that ensure that each table has similar levels of intensity and contrast. The result is that the combined “quilt” is balanced and unified visually.
Artist Sherri Grasmuck created a mosaic facade of Guatemalan women on her house in Philadelphia that is the perfect case study for choosing a grout color.
Recently, artist Jackye Mills emailed me about a problem she was having with her first mosaic project, and it really caused me a lot of angst because the artwork was a strong design that was otherwise well executed. I hated the thought that a first-time mosaicist could do such a good job on something so ambitious only to lose the project due to a technical issue.
If you work with stained glass over time you can end up with buckets full of scrap. When the pieces start getting too small and irregular, or if there’s just too much of it, you can used them in a stepping stone. This tutorial demonstrates how to make a stepping stone with an abstract pattern. You can also use tiles instead of stained glass scraps.
Ceramic tile can be used for outdoor mosaic patio tables provided you live someplace warm year round, but otherwise glass tile should be used because it is impervious to moisture and freeze damage. There are other reasons to use glass tile explained later in this article.Concrete Patio Table Set
Artist Naomi Haas recently completed a mosaic patio table set that included concrete benches, and I really liked it for several reasons. For starters, the table base and benches she had were sturdy and stable and appropriate for an outdoor mosaic (and not wood or rusted light-gauge metal or some of the other junk people email us about using).Mosaic Bench 1 of 3 uses a design of solid colors instead of being a copy of the other benches.
I also like the color scheme. Naomi colored the un-mosaiced surfaces black and used black grout to make the bright festive colors of the Mexican Talavera tile stand out. To make the concrete black, Naomi used a product called Flex Seal, but black spray paint could have been used. Another thing that draws me to this project is that Naomi made a different design for each bench instead of making them the same.
Patios are excellent locations for mosaics, but the patio floor itself is not as good a surface for a mosaic as a surrounding wall or brick planter would be. The main reason is simple: metal patio furniture will crack and crush glass tile, and glass is the preferred material because it is frost proof, economical, and comes in many colors. Also, the floor of the patio is not as visible as a nearby vertical surface is likely to be, especially when furniture, grills, and the usual patio accessories are present.
Recently artist Lisa Jones emailed me some photos of her patio mosaic, and I was taken with it in spite of my preference for designs that use free-form placement of pieces of tile instead of gridded patterns of whole tile.Lisa Jones Patio Mosaic right side continues with the garden theme and flower and bee motifs.
A few years ago, Karen J created a mosaic bench in her backyard using mining debris (large stones), cement, and chicken wire to form the base, which is similar the methods we recommend in our instructions for creating bases for outdoor mosaic sculptures. Karen modeled her bench after those made by the great mosaic architect Gaudi in Park Guell in sunny Barcelona, and she used brightly colored ceramic tile just as Gaudi had used. The problem is that Karen’s backyard is in Colorado, and so her mosaic experienced many long and hard freezes that a mosaic in Barcelona would never see.Mosaic Bench after Antoni Gaudi shows the ravages of freeze damage. Colorado winters are quite severe, but any temperature below freezing can crack and flake ceramic tile. Ceramic Tile Is Vulnerable To Freeze Damage
Glass mosaic tile is non-porous, and so water cannot seep in and freeze and crack it, and so glass is preferred for outdoor use, as is porcelain tile for the same reason. On the other hand, ceramic tile tile is very porous and soft, and so water can penetrate it (through tiny cracks in the glazing). Once this water freezes and expands, it cracks the ceramic tile and often causes the face of the tile to flake off.Mosaic Bench Detail showing freeze damage. Note that the empty sockets in the blue tile are NOT where tile has popped off. Instead, it is where the faces of the tiles have flaked off due to water freezing and expanding in tiny cracks and pores.
In the photo above, you can see how some colors were more resistant to freeze damage than others. This difference was not due to the color but to the variety of the tile: some brands of ceramic are harder and less porous than others. Also, some brands have thicker glazes, and that can also affect how permeable the tile is to water.Preventing Freeze Damage
You can minimize freeze damage by sealing your finished mosaic with multiple applications of a tile and grout sealer from your local building material store. Avoid ordering sealers online during winter months because water-based silicone sealers ruin if they freeze during shipment. You should also clean and reseal the mosaic each fall. Small mosaics such as mosaic stepping stones can be brought inside for the winter.Mosaic Bench Second Detail showing freeze damage. Imagine how bright the orange and yellow sun was before Freeze Meister blasted it and flaked off the color!
Artist Lyn Richards sent me some pictures of the mosaic bird bath she made this past summer, and it is worth showing off. The floral design and the colors used in the mosaic were inspired by Van Gogh’s painting “Irises.”Mosaic bird bath by artist Lyn Richards makes good use of contrasting colors and a Van-Gogh-inspired floral design that help integrate the bird bath with its surroundings. Note the use of an ordinary concrete stepping stone as a footing/base to keep the mosaic work separated from the soil. This is recommended because the acids in decaying organic matter slowly rot stone, concrete and grout. Material List for a Mosaic Birdbath Concrete Base
To make a mosaic bird bath such as this, you could use a ready-made concrete bird bath from a lawn and garden center, or you could make an original concrete sculpture if you are looking for something with a less conventional shape. Lyn used a ready-made concrete bird bath that came in two sections: a base column and a bowl.Thinset Mortar and Tools
Thinset mortar should be used instead of adhesive for attaching the tile. A complete list of tools and materials for mixing thinset and for applying it is given in my instructions for using thinset mortar with glass tile. (Note the instructions were written for doing extremely detailed work, so I might make thinset seem much more difficult to use than it really is.) I have also written a page for how to keep your hands clean when using thinset.Glass Mosaic Tile
Glass mosaic tile in non-porous and so water can’t get inside it and freeze and crack it all to pieces. This makes glass superior to stone and ceramic tile when used outdoors. You can use any of the glass we sell. Lyn’s mosaic was made from different brands of 3/4 inch vitreous glass tile, metallic glass tile. iridescent glass, and stained glass.
To find out how much tile you need, you can divide your shape into component surfaces and use our mosaic tile estimator. What do I mean by component surfaces? For estimation purposes, Lyn’s bath can be thought of as cylinder topped by a disk. The surface area of the cylinder is A = D*Pi*H, where D is the diameter, and Pi is 3.14, and H is the height. The surface area of the disk is A = Pi/4*D*D. Note that this time D is the diameter of the bowl and not the pedestal base. Remember to multiply the surface area of the disk by a factor of 2 because there is a top and a bottom.
As always, remember to inflate your estimate by 5 to 10% to account for cutting scrap and to provide a cushion for error in your estimates. I have always found that it is much better to have tile left over than it is to not have enough. Suppliers sell out from time to time, and the next manufacturer batch might not match what you already have, or at least match exactly. Also, leftover tile serves as inspiration and material for future projects.Finding and Transferring Patterns
Lyn used Van Gogh’s painting “Irises” for her pattern. She drew the outline of the shapes (blades and petals) onto the concrete using a pencil, and then she went over that drawing with a black Sharpie marker when she was sure she had her lines correct. This is recommended: Don’t use the marker until I work out my lines by trial and error using a pencil. If your pencil drawing gets to be a mess and you need to start over, you can “erase” it by wet sanding it and wiping it off with a rag.To create a sense of depth and shading, Lyn used multiple shades and hues of green for the leaves of the irises instead of one color. Choice of Colors and Visual Interest
Note how Lyn used multiple shades and hues of green to make the blades of the iris leaves instead of using just one type of green. This creates shade and depth and visual interest and makes all the difference in the world. Monochromatic color fields are boring, and they take just as long to tile as a more interesting mix of colors. Note the solitary pea green blade of new growth and how it stands out from the other leaves, which are a mix of darker and bluer greens. Similarly, the petals of the irises are made from multiple cyan blues and ultramarine blues instead of one color, and this makes them more lifelike and more visually appealing.Andamento and Visual Interest
The background of a mosaic is an opportunity to add visual interest to the scene and should never be “bricked” up like the tiled wall of a shower. Andamento is the visual flow of a mosaic created by arranging the tile in rows, and it can make the background of your mosaic as visually interesting as the figures in the foreground.Lyn’s strong use of andamento creates a sense of motion in the background. When used to its full potential, andamento can make the background as interesting as any figure in the foreground, as demonstrated here.
Observe how Lyn used multiple related hues for the background instead of one color. Also note there is not a single whole tile mixed in with all these cut pieces. Why not? A uniform square would stick out like a sore thumb among all the irregular pieces.Cutting and Attaching the Tiles
Thinset is concrete that hardens over time. I can usually get three hours out of a batch, and I often work in sections, usually completing about 1 or 2 square feet per session, depending on how detailed my work is. Lyn found it useful to have her tile cut up in advance of a session, but you can always make incidental cuts as needed while you are attaching tile. Again, my thinset instructions explain the details of how to handle and use the mortar to attach tiles. Tip: partially crushed liquor boxes make great cradles for holding heavy pieces of stone and concrete while you tile them.Removing Sharp Edges
A marble file or a rubbing stone can by used before the tile is mounted to remove any sharp edges. After the tile is mounted, it is a little more difficult to remove sharp edges, but gently rubbing the surface of your mosaic with a rubbing stone can help a lot.Grouting
Before grouting, you should clean off any excess thinset from the face of the tiles. Scraping this off will also make any loose tiles fall off so that you can reattach them before grouting. You should wait a day or two before grouting to let the thinset harden. Black grout is best for making your colors stand out. Lyn used a combination of black, gray, and brown grouts, and she blended these to get the exact color she wanted. A few days after your grout hardens, you should buff all the grout haze off and seal the finished mosaic with multiple applications of a silicone-based tile and grout sealer, such as available at any building material store.Lyn Richard’s mosaic bird bath at home in her garden.
Yesterday I wrote up some recommendations and instructions for Outdoor School Mosaics that focused on a project where each child made a mosaic stepping stone on a paver to be arranged in a crazy quilt design. I forgot to clarify that those instructions were written for younger students and beginners needing to play around with tile and get some basic experience forming tile into patterns and shapes. After all, it doesn’t make sense to have young children trying to copy the work of an experienced mosaic artist before they have had the benefit of handling tile long enough to make a simple triangle or smiley face.More Sophisticated Designs
If you wanted to use make a more sophisticated design with smaller pieces of tile or to render an image, you could adapt that same method and add just a few steps. I have the steps numbered below, but here is a summary of what would be different: Before you covered the cardboard square with contact paper (sticky side out), you would draw your pattern on the cardboard or tape the pattern to the cardboard. Once you position all your tile on the pattern covered in contact paper, you would use some mosaic mounting film to pick it up off the cardboard/contact paper. Then the mosaic could be pressed onto a paver or stepping stone coated with thinset. Once the thinset hardens, the mounting film is peeled off and the mosaic is grouted. This method allows you to lay up very complicated designs in advance of transferring it all at once to the cement.Pavers vs. Molds
Note that here I am talking about using thinset mortar to attach a mosaic design to an existing stepping stone or paver or flagstone. If you need instructions for how to use a stepping stone mold to press tiles into wet concrete (or pour wet concrete over a mosaic design mounted on contact paper at the bottom of a mold), then read my article on Mosaic Stepping Stone Instructions.Stepping Stone Transfer Instructions Cut out a square of cardboard the same size as your stepping stone or paver. If you want to use an irregularly shaped piece of flagstone as your mosaic base, you can cut out a piece of cardboard in the same shape as the flagstone. Just lay the flagstone on the cardboard and trace around it. Draw your mosaic pattern on the cardboard or on a piece of paper taped to the cardboard. Wrap the cardboard pattern with clear contact paper with the STICKY SIDE OUT. The sticky contact paper keeps the tiles from sliding around as you position them on the pattern. Use mosaic mounting tape (or clear packing tape) to pick the mosaic up off the cardboard pattern. Coat the paver or stepping stone or flagstone with a thin layer of thinset mortar. Smear it around to make sure the surface is wetted thoroughly and then scrape off the excess. You only need a layer about 1/16 inch thick. A little more won’t hurt, and it doesn’t have to be exact, but too much can be a little messy if you press down of the mosaic and squeeze it out the sides. Press the mosaic into the thinset. It may be easier to lay the mosaic on a table (with the mounting tape side down) and lower the thinset-covered stone onto the sheet of tile. Allow the thinset to harden for 24+ hours. Peel off the mosaic mounting tape. Grout the mosaic with additional thinset if needed. It is better to use more thinset instead of grout because it will match the color of any thinset that pressed up between the tiles when you mounted the mosaic. If you use grout, then the color probably won’t be exactly the same, and your mosaic will look like you grouted it with two different types of concrete. Often no additional grout is needed because enough thinset squeezes up between the tiles during mounting. Clean any grout residue or haze from the face of the mosaic by buffing with a clean cloth. Allow the grout to cure for 2 or 3 days and then seal the finished mosaic with a tile and grout sealer purchased from a local building material store.
For more information on using clear contact paper and mosaic mounting tape to lay up and transfer mosaic designs, read my article on Mounting A Mosaic On Clear Adhesive Film. If the cost of mosaic mounting tape is too high, or if you don’t need a whole roll, then you can use clear packing tape as a substitute.