About Grout Atlas

Grout Atlas is an independent reference site about tile grout. It exists for everyone who chooses, installs, cleans, seals or repairs grout: homeowners trying to understand why a shower joint keeps cracking, DIYers planning a first backsplash, and working tile setters who want a fast, reliable answer about a joint width, a cure time or a cleaning chemistry before they commit to a job.

Grout looks simple. It is a thin line of material between tiles, and most people only think about it when it stains, cracks or falls out. In practice it is a small engineered system: a binder, a filler, water or resin, additives, a specific joint geometry, a substrate that moves, and a surface that gets wet, scrubbed and walked on for decades. Most grout failures trace back to a mismatch somewhere in that system. Grout Atlas is built to explain the system clearly enough that readers can make good decisions and fix the right problem.

Our mission

The goal is to be the most useful single place on the web for accurate, practical information about tile grout. That means answers that are specific enough to act on (joint widths, cure windows, pH ranges, coverage figures), honest about where products differ, and anchored to the published standards and manufacturer data that the tile industry itself relies on.

We want a reader to leave a page knowing not only what to do, but why it works, what can go wrong, and which document to check before starting. Good grout work depends on following the specific product's instructions, and a reference site should make those instructions easier to understand, not replace them.

What makes Grout Atlas different

• Mechanism first. Instead of lists of tips, pages explain the underlying cause: how cement hydrates, why water-to-powder ratio controls strength and shading, why efflorescence appears, why rigid grout cracks where a movement joint belongs. The grout science section goes deepest on these mechanisms, and the rest of the site builds on them.
• Standards and data sheets as the backbone. Guidance is anchored to the ANSI A108, A118, A136 and A137 series, ISO 13007, the TCNA Handbook, and manufacturer technical data sheets (TDS) and safety data sheets (SDS). When we give a typical range, we say so, and we point to the product TDS as the final word.
• Symptom-first diagnosis. People rarely search for "differential movement at a change of plane." They search for "grout cracking in the corner of my shower." The grout problems section starts from what you can see (cracks, crumbling, dark joints, white haze, color change) and works backward to the likely causes and the right fix.
• Original computed data and free calculators. The research section publishes original tables built from published product data and joint geometry, such as coverage figures and grout joint area analysis. The tools run free in your browser and show the formulas and assumptions behind each result.
• No sponsored rankings. There are no "best grout" lists that sell placement. When we compare grout types, we compare categories and properties, and we tell you what to look for in a data sheet so you can evaluate any product yourself.

How the site is organized

Content is grouped into sections that follow the life of a grout joint, from choosing a material to keeping it clean years later. Each section has a hub page that links to every guide in it.

• Grout basics: what grout is, what it does and does not do (it is not a waterproofing layer), how long it lasts, and the vocabulary of a grout joint.
• Grout science: the chemistry and physics behind strength, shrinkage, shading, efflorescence and staining.
• Grout types: sanded, unsanded, polymer-modified, epoxy, urethane, premixed and specialty grouts, with the standards that apply to each.
• Comparisons: side-by-side breakdowns of the choices people weigh most often.
• Grout joints: joint width, depth, movement joints and where grout should give way to sealant.
• Grout by tile: how the tile itself (porcelain, natural stone, glass, mosaic, large format) changes the grout decision.
• Grout by location: showers, floors, countertops, backsplashes, outdoor areas, pools and commercial kitchens.
• How to grout: mixing, floating, sponging, haze removal, cure times and working in difficult conditions.
• Grout problems: diagnosis organized by symptom.
• Grout repair: spot repair, removal, regrouting, color matching, and when regrouting will not solve the problem.
• Grout cleaning: routine cleaning, stain removal, cleaners by pH, and mold and mildew.
• Sealing grout: whether to seal, which sealer type, how to apply it, and how to fix sealer problems.
• Tools: calculators and selectors for quantities, joint widths, sealer coverage, cure planning and diagnosis.
• Research: original reference tables and data compilations.
• Glossary: plain definitions of the terms used across the site and on product data sheets.

Answers to quick, common questions are collected on the FAQ page.

Independence

Grout Atlas does not accept payment from manufacturers, distributors or retailers for coverage, placement, rankings or favorable treatment. No company reviews or approves our pages before they are published. When a product or brand name appears, it is there only to identify a product category or to help a reader recognize what is on a store shelf, never as an endorsement.

Products within a category can behave quite differently, and formulations change. That is why our guides describe what to look for (the applicable ANSI or ISO classification, the joint width range on the TDS, the cure schedule, the cleaning restrictions) rather than telling you which brand to buy.

The full set of principles behind how pages are researched, written and maintained is published in our editorial standards.

Accuracy and corrections

Every page shows the date it was last updated. Pages are re-checked when a relevant standard is revised or when major product data changes, and on a periodic review cycle. If you find an error, an outdated figure or a claim that does not match a current standard or data sheet, please tell us. Our corrections policy explains how reports are handled and keeps a public log of substantive corrections.

How to reach us

General questions, suggestions for new guides and feedback are welcome at hello@groutatlas.com. Reports of errors go to corrections@groutatlas.com. The contact page explains what we can and cannot help with. For how we handle information about visitors, see the privacy policy.