Got a musty smell, a stain, or a feeling something's off? A room-by-room guide to where moisture hides, what to look for, and what to do when you find it.
Already know you need a lab test? Order a home mold test kit from our partner HomeSAFE.
Get a test kitMost mold information pushes a test without telling you where to look, who to call, or how the process is supposed to go. This guidebook covers all three, in the order you'd work through them. Here is what each part holds.
The biology of mold, and how it develops in a home.
Everything else in the guidebook rests on this. Once you understand what mold needs and how it spreads, the rest of the process stops feeling like guesswork.
Back up what you see with readings.
How to use a hygrometer, a moisture meter and a thermal camera, and what the readings mean.
Know what a test can and can't tell you.
What each kind of test is for, and when to skip it.
The early clues, before anyone sees mold.
Learn what the common signs look like and what they point to.
One area of the home at a time.
Interactive floor plans and checklists for 12 areas, from bathrooms to attics and crawlspaces. Try a full room below.
Two different jobs.
Who figures out what's wrong, who fixes it, and why they should be separate companies.
Moisture control, room by room.
Humidity and airflow habits, the tools that help, and what to do in each area.
This is the complete Bathrooms chapter, exactly as it works in the guidebook. Tap a numbered spot on the plan. The other eleven areas work the same way.
Bathrooms see more water and humidity than any other room. Most problems start where water is used every day. In bathrooms with persistently high humidity, shower moisture can reach cooler vent and duct surfaces, where condensation and mold spotting can develop.
You've just used one of 12 areas. The full guidebook adds the rest, plus the checklists, readings, testing and prevention chapters.
Unlock everything · $10Checkout takes about a minute, then the guidebook opens.
Pick the room you're worried about. Follow the routine, take readings, tick off the checklist.
Fix a leak yourself, run a test, or call the right kind of professional. The guidebook tells you which.
If you only want to sample or measure something, these two kits from our partner HomeSAFE are available on their own. The guidebook shows when and where to use them.
For anything you're not sure of. Swab it, mail it in, and the lab tells you whether it's mold. Identifies common indoor molds, including Aspergillus, Penicillium, and Stachybotrys.
For taking readings as you inspect. Detect moisture. Monitor humidity. Measure material moisture, indoor humidity, and temperature.
HomeSAFE is our sampling partner, and we earn a commission on kits and tools ordered through our links. Swab areas you can safely reach. Lab results show only what was sampled and aren't a diagnosis of your home.
No. It's an interactive guidebook that opens in your browser, so the floor plans and checklists work on your phone while you're standing in the room.
Enter your purchase email and we'll send a sign-in link. It works on up to 2 devices.
No guidebook can tell that from a photo or a description. It shows you how to find moisture problems, what tests can and can't tell you, and when to bring in a professional.
It's a digital product and all sales are final, which is why one free chapter is open above. Read it first.
No. Most of the guidebook is about finding and fixing moisture, which needs no kit. Kits are for when you want a sample analyzed.
We're professionals from the mold and environmental industry, and every day we answer the same questions: How do I know if it's mold? Why does this keep happening? And how do I keep it from coming back?
The Mold HQ guidebook puts those answers in your hands. It walks you through how mold grows, how to spot the moisture behind it, how testing works, and what to do from the first sign of trouble all the way through remediation. When something needs a closer look, it helps you recognize when it's time to call a professional.
We've watched people get taken advantage of because they didn't know what questions to ask, and we've seen how much confusion and fear surround the word "mold." Mold is a normal part of the world around us. What matters is understanding where it shouldn't be growing, why, and what to do about it.
Every chapter, every checklist, and the seasonal routine that keeps the moisture out.
Get the guidebook · $10