Terms of use

The drawings, materials lists and figures on this site are a planning aid. They are not engineering, architectural or legal advice, and they are not a design for any structure.

A plan works from the sizes you enter and from published documents. It can’t see your site: the soil, the slope, the frost depth, buried lines or what your neighbors’ fence stands on.

Anything that carries a load or holds back soil, such as a deck, a raised patio or a retaining wall, needs a design checked by a qualified person and, in most places, a permit.

Building codes, zoning rules and homeowners’ association rules differ by place and change over time. Where we show a city’s or state’s rule, it is the text that place published, quoted on the day we read it; it may have changed since, and your permit office has the last word.

Call 811, or use your state’s online request, a few working days before you dig. Utility companies mark buried lines for free; how many days’ notice you need depends on your state.

Follow the maker’s instructions printed on the product you buy. Where they differ from a plan, the instructions win.

Each number on the site comes from a document someone else published: a government standard, a state or city rule, a manufacturer’s data sheet or guide, or a trade association’s printed value. We name the document and its edition beside the number, and link to it where the publisher allows.

We use single values as facts. We don’t reprint other people’s tables, paragraphs or drawings; the text and the drawings on this site are our own.

QUIKRETE asks that its site not be linked without consent, so its documents are named here without a link.

Product and brand names are trademarks of their owners. Naming a product doesn’t mean its maker endorses this site, or that we endorse the product.

How we record and check each number is on the Methodology page.

The site is provided as is. We check our numbers against their documents, but a document can be wrong, out of date or replaced, and so can we. We make no promise that a plan is complete, accurate or fit for your project.

To the extent the law allows, we are not liable for losses from using the site, including materials bought, work done or damage caused on the strength of a plan.

When we find an error, we fix it and list the fix on the Corrections page.

The illustrations on the site were made for it with an AI image generator. Photos by other people may appear only under the free licenses their authors chose, each credited where it appears with its author, its source and what we changed. The photos approved for use on the site:

• 6 photos from Pexels under the Pexels License, by Los Muertos Crew, Daniel Agundiz, Boris K., Brett A.

The planners are free to use, with no account. You may link to any page and share any plan.

Please don’t copy our pages or data in bulk, or run automated tools against the planners. Ask us first; a contact address is coming.

When these terms change, the date at the top of the page changes with them. Using the site after a change means you accept the new version.