How We Fact-Check

• Each fact links to the page we read it on, preferring government agencies, licensing boards, universities, safety organizations and manufacturers.
• Before a page is published, each fact is checked against its source by a separate reviewer from the one who drafted it. The drafting and reviewing are done with AI tools. No licensed tradesperson reviews our pages.
• If we can't open or confirm a source, we leave the fact out. A blank state or city means we couldn't verify it, not that no rule exists.
• Cost figures are our own estimates. We show the math, and label what is an assumption.
• Each page shows the date it was last verified. Found an error? Tell us.

General information, not professional advice. Conditions, codes and prices vary. Turn off power, gas or water before any work, and hire a licensed professional when in doubt. Cost figures are our estimates, not quotes.