Tile installation & repair: backsplash, floor, shower — costs, materials, and grout that lasts

Three main tile categories with different installs + costs. (1) Ceramic — clay-based, fired at lower temp; affordable ($1-$5/sq ft material), softer (chips easier), best for backsplashes + low-traffic floors. (2) Porcelain — clay + finer minerals, fired hotter, much denser; $3-$15/sq ft material, harder + more water-resistant; best for floors, showers, outdoor use. Porcelain rated PEI 4-5 for floors. (3) Natural stone — marble, travertine, slate; $5-$30/sq ft material, beautiful but porous; requires sealing every 1-2 years; not ideal for kitchens (oil stains) or outdoors in freeze-thaw climates. Lowest TCO for most residential floors: 12x24 porcelain in a neutral color.

A great tile on a bad substrate cracks within a year. Three substrate types: (1) Cement backer board (Hardibacker, Durock) — required for any wet area (shower, mudroom, laundry); 1/4" for floors over plywood, 1/2" for shower walls. Adds $0.75-$1.50/sq ft. (2) Uncoupling membrane (Schluter Ditra) — flexible plastic membrane that absorbs subfloor movement; the right choice over wood subfloors prone to flex; adds $1.50-$3.00/sq ft but reduces cracking. (3) Concrete subfloor — tile direct, but check for moisture (vapor barrier needed in basements). Skipping proper substrate is the #1 cause of cracked tiles within 2 years.

Shower floors + walls get wet daily for decades. Two waterproofing systems: (1) Traditional — cement board + RedGard (paint-on liquid membrane) brushed over seams and corners. Adequate but installer-dependent. ~$200-$400 in materials. (2) Sheet membrane — Schluter Kerdi or similar, a peel-and-stick waterproof sheet adhered to drywall or backer board with thinset. More expensive ($300-$800 in materials) but bulletproof and the modern standard. Reputable pros now default to Kerdi or equivalent; if your bid uses RedGard alone, ask why. The waterproofing must extend up the wall at least 6" above the highest water source and onto the bench/curb. Get a 24-hour flood test before any tile goes in to verify the pan drains and holds water.

Two grout chemistries with very different lifespans: (1) Cement-based grout (sanded for joints >1/8"; unsanded for narrower) — $20-$40/bag; 7-10 year lifespan; needs sealing yearly; stains easily. The default. (2) Epoxy grout (Spectralock, Starlike) — $80-$200/bag; 20+ year lifespan; doesn't stain or absorb water; doesn't need sealing. The right call for showers, kitchens, and any high-traffic floor. Costs $1-$3/sq ft more in labor (harder to work with) but pays back in zero maintenance + no re-grouting. Single biggest "I wish I had spent the extra" upgrade for tile work. Color match matters: light grout shows dirt; medium grays + browns are most forgiving for floors.

A skilled tile install centers the tile in the room so cuts at the edges are roughly equal — a beginner often starts at one wall and leaves a 1" sliver against the opposite wall (looks awful). Four layout signs of a good install: (1) full tile starts at the most-visible threshold, partial cuts hidden under the toilet/cabinet/wall. (2) Cuts at corners are at least half a tile wide. (3) Lippage (height difference between adjacent tiles) is under 1/32" for honed tiles, under 1/16" for textured. (4) Movement joints (1/8" gap filled with caulk, not grout) at every wall + every 20-25 ft on large floors — required by TCNA standards. Skipping movement joints causes grout cracks within a year as the substrate expands and contracts.

Tile repairs are tricky because modern dye lots rarely match perfectly. Repair when: 1-2 cracked tiles in a non-prominent area, you have leftover tile from the original install, or only the grout has failed (re-grouting alone is $4-$8/sq ft labor). Replace when: 5+ cracked tiles indicate substrate problems, no original tile is available + visible mismatch is unacceptable, water damage shows under tiles (lift the tile to inspect), or the install is 25+ years old and you want a refresh. Pull-and-replace cost: $7-$15/sq ft. Full strip-and-redo: $12-$25/sq ft.