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Both ceramic and mosaic tiles stand up well to constant assault from water, however, which makes them very functional in the bath.

As beautiful as original wood floors can be, if you’ve ever lived with one in an old-house kitchen or bathroom, you’re aware of the issues that inevitably crop up, from cupping and rot caused by spills or leaking plumbing to burn or chatter marks from cooking and dents from chair legs.

Although flooring choices run from ancient materials like stone to newer products like engineered floors, two of the best options remain: resilient materials including linoleum and cork, and ceramic and mosaic tile. For a variety of reasons, resilients work best in the kitchen, while tile is a natural in the bathroom.

Best bet: Tile

While tile can work just as well as resilient flooring in the kitchen, tile is hard and unforgiving to both feet and breakables. Both ceramic and mosaic tiles stand up well to constant assault from water, however, which makes them very functional in the bath.

Mosaic tile was especially popular for bathrooms from about 1890 through 1930, so it hits an old-house sweet spot. In shapes that include hexagons, penny rounds, squares, and rectangles, these small pieces of ceramic are ideal for creating patterns with borders, centerpieces, snowflakes, or flowers on a tile field. Traditionally, these small decorative tiles are laid tightly together, with only 3/32″ of grout

from tile to tile. You can order premounted mosaics that produce tight grout lines from specialty retailers, or opt for tile sheets with more forgiving 1/8″ spacing.

Pro tip:Lay out a detailed map of your design on graph paper and use it to estimate how many sheets of field tile and how much border tile you need-usually more than the square footage of the floor.

Inserting decorative elements in a field mosaic floor is fairly simple.
Bo Sullivan

Surface Prep

Unlike resilients, mosaic and most other types of tile typically are not set directly over plywood. The traditional base for mosaic tile is cement or “mud,“ but many types of ceramic tile can also be laid in thinset over an industry-recommended substrate, such as cement backer board or concrete. A decoupling membrane specifically designed for tile and stone helps absorb any movement in the subfloor, minimizing the risk of cracking tiles.

Plan the Design

Mosaic tiles usually come on 12″ x 12″ sheets with mesh backing, which lay down quickly in the hands of an experienced tile setter. That said, even a floor of field mosaics-2″ hexes or 1″ penny rounds-takes a bit of planning for best appearance.

Just as with resilient tile, identify where the eye will most likely fall when you walk into the room. Measure the depth of the room from wall to wall, then snap a chalk line down the center of the room the opposite way (perpendicular) so that it bisects the focal point. Use this line to start planning the layout.

Dry lay the tile sheets, then number and stack them in order. Line up the farthest edge of a full sheet of mosaic against the line. (There will be a zigzag edge, but you’ll fill that in with a matching sheet.) Align another tile sheet below it. You want the new sheet to match the seam width of the first sheet, but you also want to hit the chalk line precisely.

When you get toward the edges of the room, you may have to cut sheets to fit with a wet saw. Don’t worry about small gaps between the edges of the tile sheets and the wall at this point. If you use a half sheet as you reach the end of a wall, use the other half to abut it when starting your next row.

Prepare the Mortar

Use a mortar specifically recommended for the circumstances of the installation. For example, the mortar for a shower installation likely will differ from one for a bathroom floor. Follow the mixing instructions exactly and mix only as much of the medium as you can use in the recommended working time (often as little as 15 to 20 minutes). Never add more water to thinset if it begins to harden, this will weaken it. The thinset should have the consistency of slightly warm cake icing.

Lay the Tile

Start in an inconspicuous area. Using a U- or V-notched trowel of the appropriate gauge (1/8″ or 3/32″, for instance), cover a small section of the substrate with thinset, enough for two side-by-side 12″ x 12″ sheets, for example. Hold the trowel at a 45-degree angle to score lines in the mortar.

Lay down just enough thinset to capture the tile without pushing out above it. (This may take some experimentation.) Lay whole sheets in a row against your chalk line or straightedge, keeping the sheets aligned as you work. Once they’re in properly, use a grout float or tap with a padded wood block to press the tiles lightly and evenly into the mortar. Applying consistent pressure will help avoid lippage, where a tile is higher or lower than neighboring tile.

To minimize visible discrepancies between the seams where the tile sheets meet, use spacers (available in 1/8″ and 3/32″ sizes). Stand up and carefully eyeball the appearance of the tile before the thinset dries. If you can tell where the seam is, you probably need to reset the tile.

Cutting Around Obstructions

If an obstruction like a toilet flange is in the way, work around it, leaving room for a full sheet of tile. Once the rest of the tile in the section is down, measure the distance from the edge of the nearest tile sheet to the flange at four points (top, bottom, both sides). Transfer these measurements to the sheet you intend to install, and use them to draw a circle on the tile. Pop out any tile that appears inside the circle with a utility knife.

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Fill In Edges

For sections less than a full sheet wide, cut the sheet to fit with a utility knife or wet saw, depending on whether or not the cut will go through tile. In areas less than one tile in width, score the tile on a snap cutter, then clip pieces off with a tile nibbler and lay them in. Once all the tile is in place, allow the floor to dry for at least 24 hours. Stay off the floor until it’s ready to grout.


If you’re using unglazed porcelain tile, apply a grout release to the surface so that the grout will not penetrate the porous tile. After the floor has dried for at least 24 hours, vacuum it to remove any loose debris. Mix a small batch of grout (sand-based is traditional); the usual formula is 1 part grout to 2 parts water. Do NOT add more water if the grout starts to dry, because it will weaken it. Once mixed to correct consistency, allow 10 minutes to set up. It should be a little looser than mayonnaise.

Lay down a thick dollop, enough for about 1² square. Using a float, spread the grout across a small section of floor, carefully working it into the seams between tiles. Once you’ve covered an area of about 3² x 3² with grout, allow it to set up for a couple of minutes. Then start removing the grout with a large sponge. Wet the sponge and wring it out so it is damp but not dripping. (Avoid adding moisture to the grout as you sponge off the excess.) Wring out the dirty sponge and clean the water as often as necessary.

Grout usually produces a haze that persists after it has been fully removed and the floor is dry. To clean it up, use a grout haze cleaner (available from builder’s supply and tile stores).

There are now membrane-thin electric radiant heating elements that can slip underneath almost any floor.

Radiant Heat: Almost Anywhere

For much of its history, under-floor radiant heating has been difficult to install and problematic as it ages.

No longer. There are now membrane-thin electric radiant heating elements that can slip underneath almost any floor. Some are even geared to retrofits, tacking up beneath existing floors with room to spare for insulation.

That said, there are some caveats about installing a real wood floor over an in-floor radiant system, or retrofitting underneath a wood floor. Most have to do with moisture and the specific characteristics of the wood itself.

That’s because radiant systems transmit warmth directly through the flooring material, usually at temperatures of 80 degrees or higher. Natural wood planks or strips can absorb and retain moisture, causing them to expand and contract when they’re heated. The dry heat from a radiant system can cause the floor to dry out quickly, leading to cupping, cracks between joints, and ultimately, surface damage.

Not all species and cuts of wood will adapt well to a radiant retrofit. Most vulnerable are soft woods like pine and hickory, especially if they’re flat-sawn. If you’re installing new flooring over radiant, opt for strip flooring rather than plank, and allow plenty of time for the wood to acclimate to the setting. Installing wood flooring with a high percentage of residual moisture over radiant heat can lead to early failure. For best results, look for a radiant product that puts out heat at a low, gentle setting, such as a low-voltage membrane.

Inserting Patterns

Inserting decorative elements in a field mosaic floor is fairly simple. When you reach a section for which you want to lay a contrasting element like a flower or snowflake, pop out the individual tiles that make up the pattern, then replace them with tiles in the chosen contrasting color. Secure them to the mesh backing with contact cement or a drop of hot glue before installing the sheet.

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