Flooring & Tile

Tile Installation Guide

How to install tile on floors and walls — substrate prep, layout lines, setting tile in thinset, cutting, grouting, and sealing — with a complete materials list.

Updated May 25, 2026

Calculators for this project

Tile is unforgiving of a bad foundation and very forgiving of patience. Most failures — cracked tiles, popping grout, lippage — trace back to the substrate or a rushed cure, not the tiling itself. This guide covers a clean install on floors and walls from prep through sealing.

What you'll need

Work out quantities first with the Tile Calculator — it gives the tile count plus the thinset, grout, backer board, and spacers to go with it. You'll also want:

  • Cement backer board (and a waterproofing membrane for wet areas).
  • Thinset mortar and grout (sanded for wider joints, unsanded for narrow).
  • A notched trowel, tile spacers, a rubber grout float, and a large sponge and bucket.
  • A tile cutter or wet saw, plus a level, chalk line, and tape measure.
  • Grout sealer (for cement-based grout) and knee pads for floors.

Step by step

  1. Prep and check the substrate. Make sure it's flat, clean, structurally sound, and rigid. Install cement backer board on floors and wet walls, and add a waterproofing membrane in showers and tub surrounds.
  2. Find your layout. Measure to the centre of the area and snap chalk lines. Dry-lay a row in both directions so cut tiles land symmetrically at the edges and you avoid a sliver against a wall.
  3. Mix the thinset. Add powder to water and mix to a peanut-butter consistency, then let it slake (rest) per the bag and remix. Only mix what you can use before it starts to set.
  4. Set the tile. Spread thinset with the flat side, then comb with the notched side held at a consistent angle. Press each tile with a slight twist, add spacers, and check level as you go. Back-butter large tiles for full coverage.
  5. Cut to fit. Measure and cut edge and corner tiles with a tile cutter or wet saw. Plan outlets and obstacles before you reach them.
  6. Let the thinset cure. Stay off the tile and wait the full cure time (commonly 24–48 hours) before grouting.
  7. Grout. Remove spacers, then press grout into the joints with a float held at 45°, working diagonally across the tiles. Wait a few minutes, then wipe with a damp (not wet) sponge, rinsing often.
  8. Clean the haze and seal. Buff off the grout haze once it's dry, let the grout fully cure, then seal cement-based grout to resist stains and moisture.

Pro tips

  • Dry-lay first to balance your cuts — never start tight against one wall.
  • Check coverage early: pull up a freshly set tile and confirm thinset covers its back with no gaps.
  • Watch for lippage (uneven tile edges); a tile-levelling system helps with large-format tile.
  • Keep joints consistent with spacers, and don't grout until the thinset is fully cured.
  • Buy from one dye lot and keep a few spare tiles for future repairs.

Common mistakes to avoid

  • Tiling over drywall in wet areas or over a flexing floor — both crack tile and grout.
  • Skipping waterproofing in showers and tub surrounds.
  • Grouting before the thinset has cured, or sealing grout before it has.
  • Starting the layout from a wall instead of the centre, leaving thin slivers at the edges.

Get your materials list

Frequently asked questions

What goes under tile?+

Tile needs a flat, rigid, and (in wet areas) waterproof substrate. On floors that usually means cement backer board or an uncoupling membrane over a sound subfloor; on shower and tub walls, cement backer board plus a waterproofing membrane. Tiling directly over regular drywall or a flexing floor is the most common cause of cracked tile and grout.

How long does thinset take to cure before grouting?+

Most thinset mortars need about 24 to 48 hours to cure before you grout, though fast-setting products are quicker — always check the bag. Grouting too early can trap moisture and weaken the bond, so wait the full time even if the surface feels firm.

What size trowel should I use for tile?+

Trowel notch size scales with tile size: roughly a 1/4 in notch for small tiles up to about 8 in, 1/2 in for tiles in the 12–16 in range, and larger or you back-butter for big-format tile. The goal is full thinset coverage under the tile with no voids — lift a tile early to check your coverage and adjust.

Do I need to seal grout?+

Cement-based (sanded and unsanded) grout is porous and should be sealed once it has fully cured — typically 48 to 72 hours after grouting — to resist stains and moisture, especially on floors and in showers. Epoxy grout does not need sealing. Re-seal cement grout periodically over the years.

How much tile and thinset do I need?+

Measure each area in square feet and add a waste allowance: about 10% for a straight layout in a square room, and 15–20% for diagonal layouts or rooms with lots of cuts. The Tile Calculator totals your areas and returns the tile count along with the thinset, grout, backer board, and spacers to match.

Plan the whole project free

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This guide is general information for planning, not professional advice. Follow local building codes and product instructions, and consult a licensed pro for structural, electrical, plumbing, or gas work.