Intermediate

Tile Installation

Floors, walls, backsplashes, and showers done right

Time: 2–5 days per area

Materials: $400–$3,500 per area

Difficulty: Intermediate

Tile is one of the most durable and water-resistant finishes you can install — but it's also one of the least forgiving. A flat, solid substrate and consistent grout joints are the foundation of a tile job that lasts decades. Rushing the layout or skimping on substrate prep is how you end up with cracked tiles and failed grout.

Step-by-Step Guide

Plan your layout

Dry-lay tiles from the center of the room outward to find your starting point. Avoid ending with slivers of tile at walls — adjust the layout so cut pieces are at least half a tile wide. Snap chalk lines to keep rows straight.

Prep the substrate

Tile needs a rigid, flat surface. For floors, install cement backer board over the subfloor. For showers and wet walls, use cement board or a waterproof membrane system. The substrate must be flat within 1/8" over 10 feet.

Apply thinset mortar

Use a notched trowel to spread thinset in sections you can tile in 20–30 minutes. Back-butter large tiles (12"×12" and up) for full coverage. Thinset coverage should be at least 95% on the back of each tile.

Set the tiles

Press tiles firmly into the thinset with a slight twisting motion. Use tile spacers for consistent grout joints. Check for lippage (uneven edges) with a straightedge as you go — adjust before the thinset sets.

Cut tiles to fit

Use a wet saw for straight cuts and a tile nipper or angle grinder for curves around pipes and outlets. Score-and-snap cutters work for straight cuts on ceramic but not porcelain — porcelain requires a wet saw.

Grout and seal

Wait 24 hours after setting before grouting. Mix grout to a peanut butter consistency and work it into joints with a rubber float at a 45° angle. Clean haze with a damp sponge before it hardens. Seal grout after 72 hours to prevent staining.

Pro Tips

For large-format tiles (18"×18" and up), use a medium-bed mortar and a larger notched trowel — standard thinset won't provide enough support and tiles will crack.

In showers, slope the floor toward the drain at 1/4" per foot. Use a pre-sloped shower pan or build the slope into the mortar bed before tiling.

Never use drywall (greenboard included) as a tile substrate in wet areas — it will fail. Use cement board or a waterproof membrane system.

Leave expansion joints (filled with caulk, not grout) at all changes of plane — floor-to-wall, wall corners, and where tile meets a different material. Grout cracks; caulk flexes.