Mold inspection before buying a house
Your home inspector doesn't test for mold. When to book a mold inspector, what it costs, how long results take, and what to ask the seller for.
Updated · By 
Ben Sikes
Should you get a mold inspection before buying a house?
Get one if your home inspection report mentions water damage, a musty smell, or a past leak. Your general inspector doesn't test for mold, so book a mold inspector the day the report lands. A lab result turns a stain into a finding you can price and put in front of the seller.
Key takeaways
- An inspection with lab testing plus typical cleanup runs $1,950 to $3,800 nationally, before anyone fixes the leak behind it.
- Book early in your window, since results come back days after the visit.
- The mold report tells you where the problem is. A remediation contractor's written bid tells you what to ask for.
How much does a mold inspection cost?
| Scope | National cost | Source |
|---|---|---|
| Inspection with lab testing, 2,500 sq ft home, two samples | $450 to $800, most pay around $500 | Fixr |
| Mold removal after the inspection | $1,500 to $3,000 | Fixr |
Kept prices every line of an inspection report for $79, usually under 4 hours, and marks the ones that need a professional quote. See Kept if the mold finding is one of many lines you need a number for.
Size and samples drive the price. Fixr says the price usually depends on square footage and how many samples are taken.
Say your report flags a water-stained basement wall and a musty smell. The inspection with lab testing runs $450 to $800. If the lab confirms mold, removal adds $1,500 to $3,000. Together that is $450 + $1,500 = $1,950 to $800 + $3,000 = $3,800. The leak repair is extra, and only a plumber's or roofer's written bid can price it.
Ask the mold inspector to quote the visit and the lab fees as separate lines. Then you know what each extra sample costs before you approve it.
How long until you get mold inspection results?
Lab analysis happens after the visit, so the report arrives later than the inspector does. Count those days against your inspection deadline before you book. Ask the inspector for a report date in writing, and ask whether the lab offers a rush.
When does your home inspection send you to a mold inspector?
Both national inspector standards leave mold out. The International Association of Certified Home Inspectors (InterNACHI) Standards of Practice say the inspector is not required to determine "the presence of mold, mildew or fungus." The American Society of Home Inspectors (ASHI) standard likewise excludes "molds and mold-like substances." So your report can point at a stain. It can't tell you what the stain is.
Watch for the lines that make a mold inspector worth calling. InterNACHI's guide to tape sampling lists them: moisture intrusion, water damage, musty odors, and conditions that invite mold. The general inspector must report active roof leaks, active plumbing leaks, and signs of active water getting into the foundation. Any of those is your cue. Visible growth is a separate case, covered below.
A past leak counts too. The Environmental Protection Agency (EPA) says water-damaged areas need drying within 24 to 48 hours to prevent mold growth. Ask through your agent when the leak happened, how it was dried, and for any past mold cleanup invoice or clearance test.
If the report lists an active leak, get a plumber or roofer to look before your deadline, as well as a mold inspector.
How serious is mold?
It depends on who lives there and whether the water stops. The same EPA guide says "molds have the potential to cause health problems." Inhaling or touching mold "may cause allergic reactions in sensitive individuals," and molds "can also cause asthma attacks in people with asthma who are allergic to mold." It can also irritate the eyes, skin, nose, throat and lungs of people with no mold allergy.
Mold also damages the house. EPA says molds "gradually destroy the things they grow on." Cleaning alone doesn't end it: "If you clean up the mold, but don't fix the water problem, then, most likely, the mold problem will come back."
What if the seller says no?
You have three choices: accept the house as is, ask for a smaller credit, or use your contract's inspection terms to walk away. Your contract sets the deadline and terms, so confirm them with your agent or attorney. Whatever you accept, get the leak fixed before you move in.
Should you test for mold if you can already see it?
Often no. "In most cases, if visible mold growth is present, sampling is unnecessary," EPA says. Go straight to a remediation contractor's bid for that spot. Keep the mold inspection for water-damaged areas where you can't see growth.
Who pays for a mold inspection, buyer or seller?
If you order the visit, plan to pay the mold inspector yourself when you book. You can then add the cost to your repair request alongside the cleanup bid.
How do I know what the rest of my list is worth?
See how to get repair estimates during the inspection period for the rest of your options.
If you're waiting on a mold lab and your window is closing, upload your inspection report to Kept and have a number behind most other lines of your request.
Sources
Cost figures are modeled from public wage and materials data unless a line says observed. Kept is accountable for the numbers on this page, and corrections go to support@usekept.com. How we price.