The tile grout reference
Get grout right the first time, and fix it when it goes wrong
Clear, standards-based answers on choosing, installing, sealing, cleaning and repairing tile grout, with the reasons behind every rule.
What is happening to your grout?
Start from the symptom. Each guide explains how to tell similar causes apart and what actually fixes it. Not sure? Try the problem diagnoser.
Start with the decision in front of you
Which Grout Do I Need? A Decision Guide by Joint, Tile, Room and Skill
A step-by-step way to choose between sanded, unsanded, high-performance, premixed, urethane, epoxy and specialty grout for any tile job.
InstallHow to Grout Tile: A Setter's Step-by-Step Method for Full, Clean Joints
The full grouting sequence a tile setter follows, from checking the joints to the final buff, with timing windows and fixes.
PlanGrout Joint Width Guide: How Wide Should Grout Lines Be?
How to set grout joint width from tile tolerances, layout and grout type, with a width table for common tile formats.
ProtectDo You Need to Seal Grout? A Decision Guide by Grout Type and Room
Whether to seal depends on grout chemistry, the room and how you clean. Use this guide and a simple water test to decide.
CleanHow to Clean Grout: A Step-by-Step Method That Starts Gentle
A least-aggressive-first grout cleaning method with dwell times, brush choices, rinse technique and the checks that keep grout and stone safe.
RepairRepair or Replace Grout? A Decision Guide: Patch, Regrout, Recolor or Retile
A practical framework for choosing between cleaning, recoloring, patching, full regrouting and retiling, with effort and time estimates for each.
Explore by topic
Grout Basics
What grout is, what it does, what it cannot do, how long it lasts and how to handle it safely.
ExploreGrout Science
The chemistry and physics behind curing, shrinkage, color, porosity and strength.
ExploreGrout Types
Every grout family, the standards behind them and how to choose the right one.
ExploreComparisons
Head-to-head matchups with side-by-side tables and a clear recommendation.
ExploreJoint Width and Layout
How wide and deep grout joints should be, and where grout must stop for movement joints.
ExploreGrout by Tile Type
Grout choice, joint width and pitfalls for each tile material.
ExploreGrout by Location
Where the tile lives changes the right grout: wet, hot, outdoor, submerged or commercial.
ExploreHow to Grout
Mixing, floating, sponging, haze removal and curing, done the way pros do it.
ExploreGrout Problems
Symptom-first diagnosis: what you see, what causes it and how to fix it.
ExploreRepair and Regrouting
Patch, remove and regrout correctly, and know when the problem is below the grout.
ExploreCleaning and Stains
Safe cleaning methods, the right chemistry for each soil, and stain-by-stain fixes.
ExploreSealing Grout
Which grouts need sealing, which sealer to use, how to apply it and how to test it.
ExploreCalculators and tools
Every tool shows its formula and assumptions, and runs entirely in your browser.
Grout Calculator: How Much Grout Do I Need?
Estimate pounds, bags or gallons of grout from tile size, thickness, joint width and area.
ToolGrout Type Selector: Which Grout Should I Use?
Five questions, a ranked recommendation, and the reasoning behind it.
ToolGrout Problem Diagnoser: What Is Wrong With My Grout?
Choose a symptom and one detail to get the most likely cause and the right guide.
ToolGrout Color Visualizer: Preview Tile and Grout Combinations
Preview tile and grout color pairs in common layouts with a measured contrast rating.
ToolGrout Sealer Calculator: How Much Sealer Do I Need?
Work out sealer quantity and linear feet of grout for applicator or full-surface sealing.
ToolGrout Joint Width Calculator (ANSI 3x Variation Rule)
Turn measurements of your actual tiles into the minimum joint width that the standard allows.
ToolGrout Cure Time Planner: When Can I Walk, Shower or Seal?
Get dated milestones for walking on, wetting, sealing and fully curing new grout.
From the Grout Atlas data
Tile size changes how much grout you live with far more than most people expect. Computed from tile geometry in our joint area analysis.
Popular comparisons
Sanded vs Unsanded Grout: Joint Width, Surfaces and Which to Use
Joint width decides most cases: unsanded under 1/8 inch, sanded at 1/8 inch and wider, with surface hardness as the tiebreaker.
Epoxy vs Cement Grout: Stain Resistance, Install Difficulty and Cost
Epoxy wins on stains, chemicals and no-seal upkeep; cement wins on ease, forgiveness and repairability. Here is how to pick.
Grout vs Caulk vs Silicone: Which Material Goes in Which Tile Joint
Grout fills the field; sealants handle corners, tubs, perimeters and counters. Compare five materials side by side and pick the right one per joint.
Understand why grout behaves the way it does
How Cement Grout Cures: Hydration, Curing vs Drying and Strength Gain
The chemistry of cement hydration in grout, why water must stay in the joint, how strength builds over weeks, and what heat, cold and dry air do.
Why Excess Water Weakens Grout: Water-Cement Ratio, Bleed and Dusting
How extra mixing, tempering and sponge water raise porosity and lower strength, and how that shows up as dusting, shading and soft joints.
Why Grout Color Varies: Pigments, Water, Light and Lime
The physics and chemistry behind grout color: pigments, light scattering in pores, mixing and sponge water, calcium hydroxide migration and why wet grout darkens.
How Grout Atlas works
Standards first
Guidance is checked against ANSI A108 and A118, ISO 13007, the TCNA Handbook and manufacturer data sheets, and we tell you when your product's data sheet overrides a general rule.
Mechanism, not myth
Every recommendation comes with the reason behind it, so you can adapt to the job in front of you instead of following rules blindly.
Independent and corrected openly
No paid placements or sponsored rankings. Pages show when they were last updated, and corrections are logged. Read our editorial standards.