We read everything that comes in. Corrections and technical questions get answered first, and usually within a few working days.
Reporting an error
This is the message we most want to receive. If a figure on the site looks wrong to you, please include:
- The page URL and, if you can, the sentence or table row in question
- What you believe the correct figure is
- Where that comes from — a specification sheet, a standard, a manual or a study
Substantive corrections are made promptly and noted on the page. Our full method, including how corrections are handled, is set out in how we research.
Questions about your own situation
We are happy to point you at the right guide, and we will say so honestly if the answer is not on the site. To make that useful, tell us the room size, the humidity and temperature readings you are seeing, and what the space is (basement, crawl space, bedroom, garage). Without those three things, any answer is guesswork.
What we cannot do is diagnose a building remotely, specify equipment for a commercial installation, or advise on health symptoms. For a persistent damp problem in the fabric of a building, or mold covering more than about 10 square feet, you need someone on site. For health concerns, speak to a doctor.
Manufacturers and retailers
You are welcome to get in touch about a specification error, a discontinued model, or a correction to how your product is described. We will fix genuine errors quickly.
We do not accept sponsored posts, paid placements, guest articles, link insertions or paid reviews, and we do not sell advertising space. Pitches of that kind will not receive a reply. See the affiliate disclosure for how the site is actually funded.
Press and permissions
To quote from a guide or reproduce one of our charts, email us with the intended use. We generally say yes to non-commercial use with a link back, and we will send you a higher-resolution version of a chart if that helps.
Privacy
Anything you send is used only to answer you. We do not add correspondents to a mailing list and we do not pass addresses on.