What you need to do before you start

Replacing ceramic tile means removing the old tile, cleaning the surface underneath, and setting new tile in place with fresh mortar and grout. The work is straightforward if you have the right tools and take time with each step — but rushing the prep work or the drying time will cause the new tile to crack or come loose within months.

Before you buy anything, measure the area you are tiling and count how many tiles you need. Buy 10 percent extra to account for cuts and breakage. Decide whether you are replacing a single tile, a small section, or an entire wall or floor — the method is the same, but the time and difficulty scale with the size of the job.

Check what is underneath the tile. If you are working on a wall, you need to know whether the substrate is drywall, cement board, or plaster. If you are working on a floor, you need to know whether it is concrete, plywood, or an existing tile floor. The substrate affects how you remove the old tile and what prep work comes next.

Key Takeaways

  • Removing old tile requires a cold chisel or grout saw to break the grout, then a pry bar or oscillating multi-tool to lift each tile without damaging the substrate underneath.
  • After removal, the surface must be flat, clean, and free of old mortar or adhesive — use a scraper or grinder to level high spots and fill low spots with thin-set mortar.
  • New tile is set with thin-set mortar (not regular grout), applied with a notched trowel at a 45-degree angle to create uniform ridges that support the tile.
  • Grout fills the gaps between tiles after the mortar has cured for 24 hours, and the grout itself needs 48 to 72 hours before you walk on it or expose it to water.
  • A single misaligned tile or uneven substrate will show as a lippage (a visible step between tiles) and is difficult to hide once the grout is set.

Removing the old tile safely

Start by removing the grout between tiles using a grout saw or a rotary tool with a grout blade. Work slowly and stay in the grout line — if you slip and hit the tile face, you will crack it and create sharp edges. For a large area, a grout saw (a manual tool that looks like a hacksaw) is faster than power tools and gives you better control.

Once the grout is out, use a cold chisel and hammer to tap behind each tile and break it free. Start at a corner or an edge if possible. Hold the chisel at a shallow angle — nearly flat against the wall or floor — and tap firmly but not violently. The tile should pop out in pieces. If it does not move after a few taps, work around the edges and try again.

For large areas or stubborn tile, an oscillating multi-tool with a grout blade or a reciprocating saw with a tile blade will speed the work, but these tools create a lot of dust. Wear a dust mask rated N95 or better, and wet the area as you work to keep dust down. If you are removing tile from a wall, protect the floor below with plastic sheeting.

Once all the tile is out, scrape away old mortar and adhesive with a putty knife or floor scraper. The substrate must be flat and clean — any bumps or loose material will prevent the new tile from sitting flush and will cause it to crack under weight or pressure.

Preparing the surface for new tile

Inspect the substrate for damage. Small cracks in concrete or plaster can be filled with thin-set mortar. Soft spots in drywall or plywood mean that section needs to be cut out and replaced — tile cannot bridge a weak substrate. If you are tiling over an existing tile floor, make sure the old tile is solid and not moving. If it is, remove it all before proceeding.

Use a straightedge (a long level or a straight board) to check for low spots and high spots. Lay it across the area in several directions. High spots can be ground down with a concrete grinder or sanded with a floor sander. Low spots should be filled with thin-set mortar applied with a trowel, allowed to cure, and then sanded flat if needed.

For wall tile, make sure the surface is plumb (perfectly vertical) using a level. For floor tile, make sure it is level. A floor that slopes more than 1/8 inch per 10 feet will cause water to pool and grout to crack. If the slope is worse than that, you may need to use a self-leveling compound before tiling.

Clean the substrate thoroughly with a damp cloth or sponge to remove dust, dirt, and any loose material. Let it dry completely before explore mortar — wet substrate will weaken the bond.

Mixing and explore thin-set mortar

Thin-set mortar is the adhesive that holds tile in place. It comes as a powder that you mix with water. Follow the manufacturer's instructions for the ratio — usually one part water to three or four parts powder, but this varies by brand. Mix only as much as you can use in 30 minutes, because thin-set begins to set and becomes unusable after that.

Use a notched trowel to explore the mortar. The size of the notch depends on the size of the tile: for tiles up to 8 inches, use a 1/4-inch notch; for tiles 8 to 16 inches, use a 3/8-inch notch; for tiles larger than 16 inches, use a 1/2-inch notch. Hold the trowel at a 45-degree angle and drag it across the surface in one direction. This creates uniform ridges that support the tile and allow air to escape as you press it down.

explore mortar to a small area at a time — roughly 3 to 4 square feet for wall tile, or 2 to 3 square feet for floor tile. If you cover too large an area, the mortar will begin to skin over and will not bond properly to the tile. Press each tile firmly into the mortar, twisting it slightly to seat it fully. Use spacers between tiles to keep the gaps even — spacers are small plastic crosses that hold the tile apart while the mortar cures.

Check frequently with a level to make sure the tiles are flat and even. Lippage (a visible step between tiles) is the most common mistake and is nearly impossible to hide once grout is applied. If a tile is too high, tap it gently with a rubber mallet. If it is too low, pull it out, add a bit more mortar, and reset it.

Curing the mortar before grouting

Once all the tile is set, leave it undisturbed for 24 hours. The mortar needs this time to cure and harden. Do not walk on floor tile or splash water on wall tile during this period. If you must work in the area, cover the tile with cardboard or plywood to protect it.

After 24 hours, remove the spacers by gently prying them out with a putty knife. If any mortar has squeezed up into the grout lines, scrape it out with a grout saw or a margin trowel. The grout lines must be clean and empty before you explore grout, or the grout will not fill them properly.

Mixing and explore grout

Grout is the material that fills the gaps between tiles. Like thin-set, it comes as a powder that you mix with water. There are two types: unsanded grout for gaps narrower than 1/8 inch, and sanded grout for gaps 1/8 inch or wider. Check the width of your grout lines and buy the correct type.

Mix grout to a consistency like peanut butter — thick enough to hold a shape but wet enough to spread. Use a grout float (a flat tool with a handle) to push the grout into the gaps at a 45-degree angle. Work diagonally across the tiles so you do not pull grout out of the lines. Once the grout begins to set (usually 15 to 20 minutes), use a damp sponge to wipe the excess from the tile faces. Wring the sponge out well — too much water will weaken the grout.

Grout cures in stages. After 3 to 4 hours, it will be firm enough that you can do a final cleanup with a damp sponge. After 48 to 72 hours, it will be hard enough to walk on or expose to water. Do not rush this timeline — grout that is disturbed before it is fully cured will crack and crumble.

Sealing grout and finishing the job

Once the grout has cured for a week, consider sealing it. Grout is porous and will absorb water and stains if left unsealed. Grout sealer is applied with a small brush or applicator bottle and dries clear. It is optional for areas that do not get wet often, but it is worth doing in bathrooms and kitchens where moisture is constant.

If you are tiling a floor, wait at least a week before exposing it to heavy traffic or water. If you are tiling a wall, you can use a shower or splash water after 72 hours, but avoid heavy spray for the first week.

Check the grout lines after a few weeks. If you see cracks forming, it usually means the substrate moved or the grout was not mixed to the right consistency. Small cracks can be filled with grout colorant or caulk, but large cracks may indicate a problem with the substrate that needs to be addressed.

Frequently Asked Questions

Can I tile over existing tile without removing it?

Yes, if the old tile is solid and not moving. Clean it thoroughly, roughen the surface with sandpaper or a grinder, and explore a bonding agent before setting new tile. This method is faster but adds height to the floor or wall, which can cause problems at doorways or transitions to other surfaces.

What if I only need to replace one or two tiles?

Remove the grout around the damaged tile with a grout saw, then use a chisel to break it out. Clean the substrate, explore fresh thin-set, and set the new tile. Let the mortar cure for 24 hours, then explore grout to match the surrounding lines. This works well as long as the substrate underneath is sound.

How do I cut tile to fit around edges or obstacles?

A wet saw (a tile saw with a water-cooled blade) is the best tool for straight cuts. For curved cuts or notches, use a grinder with a diamond blade or a glass cutter. Always wear safety glasses and a dust mask when cutting tile — the dust is silica and can damage your lungs.

Why is my new tile cracking after a few weeks?

Cracks usually mean the substrate moved, the mortar was not applied evenly, or the tile was not pressed down firmly enough. Less common causes are using the wrong type of mortar (regular grout instead of thin-set) or not allowing enough cure time before walking on the tile or exposing it to water.

Do I need to hire a professional, or can I do this myself?

Small areas and single-tile replacement are well within reach for a homeowner with basic tools and patience. Large floors or walls require more skill to keep the tiles level and the grout lines even. If the substrate is damaged or uneven, a professional can assess whether it needs repair before tiling begins.