Tile Installation Guide

Complete guide to tile installation covering substrate preparation, thinset selection, tile spacing and layout, cutting techniques, grouting procedures, and sealing for ceramic, porcelain, and natural stone tiles.

Substrate Preparation Requirements

Critical Foundation Rules

The substrate is 90% of a successful tile installation. Poor substrate preparation is the leading cause of tile failure including cracking, lippage, and delamination.

Golden Rule: Substrate must be clean, flat, structurally sound, and properly waterproofed before any tile is set.

Substrate Requirements by Type

Substrate Type	Flatness Requirement	Deflection Limit	Special Requirements
Concrete Slab	1/8" in 10 feet	L/360 (rigid)	Cure 28 days, no cracks, moisture test
Cement Backer Board	1/8" in 10 feet	L/360	Fasten every 8" edges, 12" field
Plywood Subfloor	1/8" in 10 feet	L/360	Min 1-1/8" thick, exterior grade
Mortar Bed (Mud)	1/8" in 10 feet	L/360	1-1/4" min, reinforced with wire
Existing Tile	1/8" in 10 feet	L/360	Must be bonded, clean, scarified

Wood Subfloor Preparation

Minimum thickness: 1-1/8" combined (3/4" subfloor + 1/2" backer)
Joist spacing: 16" on center maximum (12" for large tiles)
Install backer board: 1/2" or 5/8" cement board required
Screw spacing: 8" on center along edges, 12" in field
Seams: Offset backer board seams from subfloor seams
Gaps: 1/8" gaps between backer boards, tape with mesh

Concrete Slab Preparation

Cure time: Minimum 28 days for new concrete
Moisture test: Max 3 lbs/1000 sq ft/24 hrs or 75% RH
Crack repair: Fill cracks over 1/16" with epoxy or leveler
Cleaning: Remove oil, grease, paint, curing compounds
Leveling: Use self-leveling compound for low spots
Grinding: Grind high spots, remove ridges and bumps

Waterproofing Requirements

Showers/tubs: Waterproof entire enclosure with membrane system (RedGard, Schluter, etc.)
Bathroom floors: Waterproof entire floor extending 6" up walls
Kitchen floors: Waterproofing recommended but not always required
Membrane types: Sheet (Schluter KERDI), liquid (RedGard), or traditional pan liner
Seams and corners: Use fabric reinforcement at changes of plane
Penetrations: Seal all pipe and drain penetrations properly

Thinset Mortar Selection

Unmodified Thinset

Basic cement-based mortar

• Best for: Over waterproof membranes (Schluter)
• Tile types: Porcelain, ceramic, stone
• Substrates: Cement board, concrete
• Open time: 15-20 minutes
• Coverage: 95 sq ft/50 lb bag (3/16" trowel)
• Cost: $12-18 per 50 lb bag

Modified Thinset

Polymer-modified (most common)

• Best for: Most installations, general purpose
• Tile types: All ceramic, porcelain, stone
• Substrates: Cement board, concrete, plywood
• Open time: 20-30 minutes
• Coverage: 85 sq ft/50 lb bag (3/16" trowel)
• Cost: $18-28 per 50 lb bag

Large Tile Mortar (LFT)

For tiles 12x12" and larger

• Best for: Large format tile, slab tile
• Tile types: Porcelain panels, large stone
• Substrates: Any approved substrate
• Open time: 30-40 minutes (extended)
• Coverage: 60-70 sq ft/50 lb bag (1/2" trowel)
• Cost: $25-40 per 50 lb bag

Glass Tile Mortar

White, non-sag formula

• Best for: Glass tile, glass mosaic
• Tile types: Translucent glass, back-painted
• Substrates: Cement board, waterproof membrane
• Open time: 20-30 minutes
• Coverage: 70-90 sq ft/50 lb bag
• Cost: $30-45 per 50 lb bag

Rapid Set Thinset

Fast-setting formula

• Best for: Quick turnaround projects
• Tile types: Most tile types
• Substrates: All approved substrates
• Open time: 10-15 minutes (very fast)
• Walk time: 3-4 hours, grout in 24 hours
• Cost: $35-50 per 50 lb bag

Epoxy Mortar

Chemical-resistant, premium

• Best for: Commercial kitchens, wet areas
• Tile types: All types, especially large
• Substrates: Any, including metal and fiberglass
• Open time: 45-60 minutes
• Coverage: 40-60 sq ft per unit
• Cost: $80-150 per unit

Thinset Selection Guide

Standard ceramic tile (under 12x12"): Modified thinset
Porcelain tile (any size): Modified or large tile mortar
Large format (12x12" and up): Large tile mortar (LFT)
Glass tile and mosaic: White glass tile mortar
Natural stone (marble, granite): White or light gray modified thinset
Over Schluter/KERDI membrane: Unmodified thinset (per manufacturer)
Shower walls: Non-sag or medium bed mortar
Fast project timeline: Rapid set thinset

Trowel Size Selection & Technique

Trowel Size by Tile Size

Tile Size	Floor Trowel	Wall Trowel	Coverage (sq ft/bag)
2x2" to 4x4" mosaic	3/16" x 3/16" square notch	3/16" x 3/16" square notch	95-115 sq ft
4x4" to 8x8" tile	1/4" x 1/4" square notch	1/4" x 3/16" square notch	85-100 sq ft
8x8" to 16x16" tile	1/4" x 3/8" square notch	1/4" x 1/4" square notch	75-95 sq ft
12x12" to 18x18" tile	1/2" x 1/2" square notch	1/4" x 3/8" square notch	60-75 sq ft
18x18" and larger	1/2" x 1/2" or 3/4" x 3/4"	1/2" x 1/2" square notch	40-60 sq ft

Proper Troweling Technique

Step 1: Apply mortar with flat side of trowel
Step 2: Comb with notched side at 45-60° angle
Step 3: Trowel in straight lines (all one direction)
Coverage: Apply only what you can tile in 15-20 minutes
Back buttering: Apply thin layer to back of large tiles
Goal: Achieve minimum 95% coverage on tile back

Common Troweling Mistakes

Using wrong trowel size (causes voids, poor coverage)
Holding trowel too flat (ridges collapse, inadequate mortar)
Swirling or circular motion (traps air, reduces bond)
Not back buttering large tiles (poor coverage, voids)
Applying too much at once (mortar skins over)
Setting tile after open time exceeded (bond failure)

Tile Spacing & Layout Planning

Layout Planning Principles

Proper layout prevents awkward cuts, ensures symmetry, and creates a professional appearance. Always dry-lay tiles and plan cuts before mixing any mortar.

Rule: Avoid tile slivers (cuts under 2" wide). Center layout or adjust grout lines to maintain full or near-full tiles in visible areas.

Standard Grout Joint Sizes

Tile Type	Minimum Joint	Recommended Joint	Notes
Rectified porcelain	1/16" (1.5mm)	1/8" (3mm)	Can achieve thin grout lines
Standard ceramic tile	1/8" (3mm)	3/16" (5mm)	Most common floor tile
Natural stone	1/8" (3mm)	1/4" (6mm)	Wider joint hides irregularities
Rustic/handmade tile	3/16" (5mm)	1/4" to 3/8"	Wider joints complement style
Mosaic (mesh mounted)	1/16" (1.5mm)	1/8" (3mm)	Pre-spaced on mesh

Layout Best Practices

Find center of room, snap chalk lines forming cross
Dry-lay tiles with spacers to check pattern and cuts
Adjust center line if cuts at walls are too small
Plan for focal points (fireplace, entry, vanity)
Use full tiles in high-visibility areas
Hide small cuts in corners, under cabinets, or behind doors

Pattern Layouts

Straight lay (grid): Simplest, tiles aligned in rows and columns
Brick/running bond: Offset by 50%, like brick wall pattern
1/3 offset: Modern look, offset by 33% (popular with plank tiles)
Diagonal: Tiles at 45°, makes room appear larger, more cuts
Herringbone: Rectangular tiles in V-pattern, labor intensive
Versailles: Multiple sizes in repeating pattern, complex
Pinwheel: Small squares with larger tiles, vintage look

Tile Spacer Usage

• Use plastic spacers sized to your grout joint (1/16", 1/8", 3/16", 1/4")
• Place spacers at each corner where four tiles meet (+ configuration)
• For wall tile, use at top and bottom of each tile for consistent height
• Remove spacers before mortar fully sets (after 30-60 minutes)
• For rectified tile, can use thin spacers or tile-on-tile with minimal joint
• Consider self-leveling spacers (clips) for large format tile to prevent lippage

Tile Cutting Techniques & Tools

Manual Tile Cutter (Snap Cutter)

Best for: Straight cuts on ceramic and soft tiles

Technique: Score once firmly, snap by pressing handles
Tiles: Works on ceramic, soft porcelain up to 1/2" thick
Advantages: No dust, quiet, portable, no power needed
Limitations: Straight cuts only, not for hard porcelain
Cost: $30-200 depending on quality

Wet Tile Saw

Best for: All cuts, all tile types (essential tool)

Technique: Feed tile slowly into spinning blade with water
Tiles: Cuts any tile type including porcelain, stone, glass
Advantages: Clean cuts, precision, notches, 45° miters
Blade: Diamond blade, replace when cutting slows
Cost: $100-600 (rent $50-75/day)

Angle Grinder with Diamond Blade

Best for: Curved cuts, notches, detail work

Technique: Secure tile, cut slowly following marked line
Uses: Curves, circles, irregular shapes, small notches
Safety: Creates dust, requires eye protection and respirator
Blade: 4-4.5" diamond blade for tile/stone
Cost: $40-150 grinder + $15-30 diamond blade

Tile Nippers

Best for: Small cuts, irregular shapes, trimming

Technique: Bite away small pieces at edge of tile
Uses: Toilet flanges, pipe notches, fine-tuning cuts
Technique: Take small bites (1/8"-1/4") to avoid breaking tile
Finish: Rough edge, plan for area to be covered
Cost: $10-30 for quality pair

Hole Saw & Diamond Core Bit

Best for: Circular cuts for pipes, drains

Setup: Use drill guide or tape to prevent walking
Technique: Start at angle, then straighten once bit bites
Cooling: Use water to cool bit and reduce dust
Sizes: Common sizes 3/4", 1", 1-1/4", 1-1/2", 2"
Cost: $15-40 per diamond core bit

Oscillating Multi-Tool

Best for: Undercutting door jambs, trim cuts

Use: Cut door jambs/casings to slide tile underneath
Blade: Wood/metal cutting blade for jambs
Guide: Use tile as height guide for perfect clearance
Tile cutting: Can make plunge cuts with carbide blade
Cost: $60-200 for tool + blades

Cutting Tips for Clean Results

• Always mark cut line on face of tile with pencil or marker
• Cut tile face-up on wet saw for cleanest edge
• Support tile on both sides of cut to prevent breaking
• Feed tile slowly and steadily into saw blade (don't force)
• For L-shaped notches, make two separate cuts rather than trying to turn tile
• Keep water reservoir full on wet saw for cooling and dust control
• Wear safety glasses, hearing protection, and respirator when cutting
• Make test cuts on scrap tile to verify measurements before cutting final piece

Grouting Procedures & Techniques

Grouting Timeline

Wait time: 24-72 hours after setting tile (check thinset package)
Rapid set thinset: Can grout in as little as 3-4 hours
Traditional thinset: Wait 24 hours minimum (48-72 hours preferred)
Test: Press tile, if it moves or mortar is soft, wait longer

Sanded Grout

For joints 1/8" and wider

• Best for: Floor tile, joints 1/8" to 5/8"
• Strength: Sand adds strength for wide joints
• Scratch risk: Can scratch soft stone or glass
• Colors: Wide variety available
• Cost: $12-25 per 25 lb bag

Unsanded Grout

For joints under 1/8"

• Best for: Rectified tile, tight joints, walls
• Joints: 1/16" to 1/8" maximum
• Finish: Smoother than sanded
• Uses: Glass tile, polished marble, thin joints
• Cost: $15-30 per 25 lb bag

Epoxy Grout

Premium, stain-resistant

• Best for: Kitchens, showers, high-moisture
• Benefits: Stain-proof, no sealing required
• Difficulty: Harder to work, sticky, requires skill
• Clean-up: Must clean within working time
• Cost: $50-100 per kit (more expensive)

Grouting Process Steps

1.Remove spacers: Pull all tile spacers from joints
2.Clean joints: Vacuum or wipe out debris from grout lines
3.Mix grout: Add powder to water (not reverse), mix to peanut butter consistency
4.Slake: Let grout rest 5-10 minutes, then remix (don't add more water)
5.Apply grout: Use rubber float at 45° angle, force into joints
6.Remove excess: Hold float at 90° angle, scrape diagonally across tiles
7.Wait: Let grout firm up 15-30 minutes until hazy on tile surface
8.Sponge clean: Use damp (not wet) sponge in circular motion
9.Rinse sponge: Frequently rinse and wring out sponge thoroughly
10.Final polish: After 1-2 hours, buff haze with dry microfiber cloth

Grouting Best Practices

Work in small sections (3-4 sq ft at a time)
Force grout deep into joints using float pressure
Use barely damp sponge (too wet will weaken grout)
Tool joints to uniform depth before cleaning
Change rinse water frequently to avoid residue
Wait 72 hours before sealing grout

Common Grouting Mistakes

Grouting too soon (thinset not cured, tiles shift)
Using too much water in mix (weakens grout)
Cleaning too early (pulls grout out of joints)
Using soaking wet sponge (causes pinholes)
Not removing all haze (dried grout is hard to remove)
Sealing too soon (traps moisture, causes failure)

Step-by-Step Installation Process

Prepare & Waterproof Substrate

•Verify substrate meets flatness requirements: 1/8" in 10 feet
•Install cement backer board over wood subfloors (1/2" thick minimum)
•Fasten backer board every 8" on edges, 12" in field with proper screws
•Apply waterproof membrane to entire shower/tub area or bathroom floor
•Seal all corners, seams, and penetrations per manufacturer instructions
•Allow waterproofing to cure fully before tiling (typically 24-48 hours)

Plan Layout & Dry Fit Tiles

•Find center of room or wall, snap perpendicular chalk lines
•Dry-lay tiles with spacers to verify pattern and check edge cuts
•Adjust layout to avoid narrow cuts (under 2" wide) at walls
•Plan focal areas to use full tiles (shower niche, vanity area, entry)
•Mark reference lines for starting point and key alignment areas
•Number or mark tiles if creating specific pattern or color blend

Mix & Apply Thinset Mortar

•Mix thinset to smooth, lump-free consistency (like peanut butter)
•Let mortar slake 5-10 minutes, then remix without adding water
•Apply mortar with flat side of trowel to substrate
•Comb with notched trowel at 45-60° angle in straight lines
•Cover only area you can tile in 15-20 minutes (check open time)
•For large tiles (12x12"+), back-butter tile back with mortar layer

Set First Tiles & Establish Lines

•Set first tile at intersection of layout lines
•Press firmly with slight twisting motion to embed in mortar
•Place spacers at corners to maintain consistent grout joint width
•Set adjacent tiles following layout lines precisely
•Use level frequently to ensure tiles are flat and even
•Check for proper coverage by lifting tile (should be 95% covered)

Continue Tiling Field Area

•Work in small sections maintaining consistent spacing
•Use spacers at every corner where tiles meet
•Check for lippage (uneven edges) and adjust while mortar is workable
•Beat in tiles with rubber mallet or beating block if needed
•Clean excess mortar from joints before it hardens (within 30 minutes)
•Step back frequently to check alignment and pattern

Cut & Install Edge & Trim Tiles

•Measure each cut individually (walls rarely perfectly straight)
•Mark cut lines clearly on tile face
•Cut tiles using wet saw for straight cuts, grinder for curves
•Test fit cuts before applying mortar (easier to recut now)
•Install cut tiles maintaining consistent grout joints
•For outside corners, use bullnose or Schluter metal edge trim

Install Specialty Cuts & Obstacles

•Create cardboard templates for complex cuts (pipes, outlets, toilets)
•Use hole saw or diamond core bit for circular penetrations
•Cut holes 1/4" larger than pipe for clearance and cover with escutcheon
•Undercut door jambs with oscillating tool to slide tile underneath
•For outlets, turn off power and cut tile to fit around box
•Install any tile accessories (soap dishes, shelves) while setting tile

Allow Thinset to Cure

•Wait minimum 24 hours before grouting (48-72 hours is better)
•Check manufacturer's instructions for specific cure times
•For rapid-set thinset, may grout in as little as 3-4 hours
•Test by pressing on tiles - if they move, wait longer
•Remove any spacers that will interfere with grouting
•Clean joints of any mortar residue or debris

Grout Tile Joints

•Remove all remaining spacers and clean joints thoroughly
•Mix grout to proper consistency, let slake 5-10 minutes, remix
•Apply grout with rubber float at 45° angle, forcing into joints
•Work in 3-4 sq ft sections at a time
•Remove excess with float held at 90° angle, scraping diagonally
•After 15-30 minutes, clean with barely damp sponge in circular motion
•Rinse sponge frequently, wring thoroughly, avoid over-wetting
•After 1-2 hours, buff haze with dry microfiber cloth

Seal & Final Finishing

•Wait 72 hours minimum before sealing grout (check package)
•Apply grout sealer with brush or applicator to grout lines only
•Wipe excess sealer from tile surface immediately
•Natural stone: seal entire tile surface with stone sealer
•Apply second coat of sealer per manufacturer recommendation
•Install transition trim, thresholds, or edge pieces
•Caulk changes of plane (floor to wall, tub to tile) with matching caulk
•Wait 24-48 hours before exposing to water or heavy traffic

Best Practices & Common Mistakes

DO:

Ensure substrate is flat, clean, and structurally sound before tiling
Use waterproof membrane in all wet areas (showers, tubs, bathroom floors)
Select appropriate thinset and trowel size for your tile type and size
Back-butter large format tiles (12x12" and larger) for better coverage
Plan layout carefully to avoid narrow cuts and ensure symmetry
Wait full cure time before grouting (minimum 24 hours, 48-72 preferred)
Use proper grout type for your joint width and tile type
Seal grout and natural stone tiles after proper cure time

DON'T:

Install tile over uneven substrate (causes cracking and lippage)
Skip waterproofing in wet areas (leads to rot and mold)
Use wrong trowel size (causes hollow spots and poor adhesion)
Exceed mortar open time (reduces bond strength significantly)
Grout too soon before thinset cures (tiles shift, grout cracks)
Add water to grout during application (weakens and causes failure)
Use soaking wet sponge when cleaning grout (pulls out of joints)
Install tile directly on plywood without backer board (deflection causes cracks)