Editorial Standards

These standards describe how Grout Atlas pages are researched, written, checked and kept current. They apply to every guide, comparison, calculator and data table on the site. The aim is simple: a reader should be able to trust a number on this site, know where it came from, and know when to check something more specific.

Sourcing hierarchy

Not all sources carry the same weight. When sources disagree, the higher source in this list wins, and where a real disagreement matters to the reader, the page says so.

1. Consensus standards. The ANSI A108 series (installation, including A108.10 for grout installation and A108.02 general requirements), the ANSI A118 series (material specifications, including A118.3 epoxy grout, A118.6 standard cement grout, A118.7 high-performance cement grout and A118.8 modified epoxy emulsion), ANSI A136.1 (organic adhesives), ANSI A137.1 (ceramic tile) and related documents, ISO 13007 (including ISO 13007-3 grout classifications such as CG1, CG2, CG2WA, CG2F and RG), and the TCNA Handbook for Ceramic, Glass, and Stone Tile Installation, including its movement joint guidance (EJ171).
2. Manufacturer technical data sheets and safety data sheets. A product's TDS states its classification, joint width range, mixing ratio, working time, cure schedule and cleaning restrictions. Its SDS states hazards and handling requirements. For anything specific to one product, these documents are the authority.
3. Natural Stone Institute and trade association guidance. Used for stone-specific care, cleaning chemistry limits and industry best practice not covered in detail by the standards.
4. Materials science literature. Textbooks and published research on cement hydration, polymer modification, epoxy chemistry, efflorescence, shrinkage and staining. Used mainly to explain mechanisms, not to set installation rules.
5. Established trade practice. Some useful knowledge is not written in any standard: how setters judge when to sponge, how to read a crack pattern, which shortcuts tend to fail. We include it because it is valuable, but we label it as trade practice (for example in "Field note" boxes) so it is never confused with a published requirement.

We cite references by name at the end of each guide. We do not cite sources we have not checked, and we do not attribute claims to standards that do not make them.

How numbers are presented

Grout products vary. Two sanded cement grouts that both meet ANSI A118.7 can have different maximum joint widths, pot lives and wait times before sealing. For that reason:

• Numbers are given as typical ranges drawn from standards and from the spread of published data sheets, and they are labeled as typical.
• Where a standard sets a requirement, we say which standard and avoid paraphrasing it into something stricter or looser than it is.
• We always direct the reader to the specific product's TDS as the final authority on mixing, joint width, cure time and use limits.
• US units come first (inches, pounds, square feet, degrees Fahrenheit), with metric in parentheses where it helps.
• Temperatures, humidity and substrate conditions change cure behavior, so cure times are presented with the conditions they assume.

How calculators and data tables are built

The tools and the research tables are built from geometry, published product data and stated assumptions. For each one:

• The formula is shown, so the result can be checked by hand.
• Assumptions are stated, such as joint depth equal to tile thickness, a waste allowance, or a typical grout density.
• Inputs are limited to realistic ranges, and results that fall outside typical product limits trigger a note to check the TDS.
• Results are estimates. Manufacturer coverage charts, where available, take priority for ordering a specific product.

Computed data is described as computed. We do not present a calculation as a measurement, and we do not present a measurement we have not made.

Writing standards

• Answer first. Each guide opens with a direct answer to the question it covers, then explains the reasoning.
• Explain the mechanism. Recommendations come with the reason behind them, so readers can handle cases the page does not cover.
• One page, one job. Science pages explain mechanisms, problem pages diagnose, and how-to pages give procedures. Pages link to their neighbors rather than repeating them.
• Tradeoffs stated plainly. Epoxy grout resists stains but is harder to install; sanded grout is durable but can scratch polished stone and glass. We do not present any option as right for every job.
• Plain language. Technical terms are defined in context or in the glossary.

Review and update process

Every page displays an updated date showing when it was last revised. That date changes when the content changes in a meaningful way, not for cosmetic edits.

• Pages are re-checked when a relevant standard is revised or when major product data changes, for example when a common grout category changes its typical joint width range or cure guidance.
• All pages are also reviewed on a periodic cycle, with priority given to pages about safety, chemistry and cure times.
• Reader reports of errors trigger an immediate review of the page in question, as described in our corrections policy.

Safety first

Grout work involves real hazards: cement is alkaline and can cause skin burns, cutting and removing grout can release respirable crystalline silica dust, epoxy components can cause sensitization, and many cleaners are hazardous when mixed (bleach with acids or ammonia, for example). Our policy is:

• Where a task carries a meaningful hazard, the page says so near the step where it matters, not only at the bottom.
• We point readers to the product SDS and to appropriate protective equipment such as gloves, eye protection and respiratory protection for dust.
• We do not recommend mixing chemicals or using products outside their labeled use.
• Where a symptom can indicate a leak, water damage or a structural problem, the page says when to stop and involve a qualified professional. See the guide to grout that stays wet or dark and when regrouting will not work for examples.

Independence and product neutrality

Grout Atlas does not accept payment, free product or other consideration from manufacturers, distributors or retailers in exchange for coverage, placement or favorable treatment, and no outside company reviews pages before publication. Comparisons are made between product categories and their properties.

When a brand or product name appears, it is only to identify a category or help readers recognize a product, and the description must be accurate and neutral. We do not publish brand price comparisons or "best product" rankings.

Corrections

When we get something wrong, we fix it. Errors can be reported to corrections@groutatlas.com. Reports are reviewed against the sources above; confirmed errors are corrected, the page's updated date changes, and substantive corrections are noted on the page and listed in the public log. The full policy is on the corrections page.

What we do not do

• We do not fabricate tests, lab results or product trials, and we do not claim to have tested anything we have not.
• We do not invent statistics, surveys, studies or quotes.
• We do not accept paid placements, sponsored rankings or paid reviews.
• We do not present trade practice as a code or standard requirement.
• We do not diagnose individual jobs remotely or recommend specific contractors.

For more about the site and how it is organized, see About Grout Atlas. Questions about these standards are welcome via the contact page.