Colophon
Editorial standards
How the pages are sourced, how safety statements are handled, and what happens when we get something wrong.
A guide about materials that people mix, dig, cut and breathe needs rules about what it will and will not say. These are ours. They apply to every page, from the long reference pieces on grading to the short notes on delivery tickets.
Where facts come from
Every figure, date, rule and definition on this site comes from a page that an editor opened and read: geological surveys, mine and workplace-safety regulators, environmental agencies, road and transport bodies, universities and their extension services. Trade associations are used only for neutral technical definitions, never for claims about products. If a number cannot be traced to such a page, we leave it out or describe the point in general words.
Safety and health statements
Where a page deals with silica dust, play sand or pool filters, we state what the public body says, in its own terms, and name the body in the sentence. We do not make a claim stronger than the source does. We never interpret an individual's exposure, symptoms or test result, and we do not explain how to comply with a particular law. Readers are sent to their own regulator, because requirements differ by country and by site. The page on silica dust and quarry safety is the fullest example.
No products, producers or prices
We do not name or link producers, suppliers, brands or contractors, we publish no prices, and we do not recommend what to buy. Where a page explains how to choose material, it stays at the level of general properties such as size, shape and cleanliness. The crushed stone bases page shows the approach.
Links and independence
Outbound links on this site are citations to the sources we used, and they are marked as such. Nobody pays to be mentioned. There are no advertisements, no sponsored text and no affiliate links.
Updates and corrections
Each page shows the date it was last updated. When a source changes, or a reader shows us an error, we correct the page and change the date. Use the contact page to report a mistake or to suggest a public source we should read.
The short version
Opened sources only, safety claims stated as the public body states them, no products or prices, and a visible date on every page.