Mold decision tool.
Three questions, thirty seconds, plain-English answer. Test, remediate, or wait and monitor; built from what we actually do in the St. Louis metro.
Try the tool
Should I test for mold,
or skip straight to remediation?
Most St. Louis homeowners with visible mold under 10 square feet do not need a third-party test, but air-quality testing makes sense if anyone in the household has respiratory symptoms, immune issues, or if you are mid-purchase or mid-sale of the property. Three questions below.
Free Tool
Should you test for mold?
Answer five quick questions. We’ll tell you whether you need a professional test, immediate remediation, or just observation. Based on Gateway’s protocol from hundreds of St. Louis-area jobs.
When testing is worth the cost
Three scenarios.
Professional mold testing runs $300 to $600 in the St. Louis metro and produces a written lab report. The report is valuable in three specific scenarios:
Hidden growth. Visible mold is just the edge of what you have. If you can see staining behind drywall, under flooring, or inside HVAC and you cannot confirm species or extent without invasive inspection, a swab and air sample tell you what is actually there.
Health stakes. A household member has asthma, is immunocompromised, or is pregnant, and you need to confirm Stachybotrys (toxic) versus common Cladosporium (allergenic but routine). The species matters for treatment decisions.
Real estate transaction. You are mid-purchase or mid-sale, the other party flagged mold, and you need a third-party lab report to negotiate price, complete the sale, or document remediation for the buyer's lender.
For routine visible growth on bathroom tile, kitchen ceiling, or basement walls under 10 square feet, testing rarely changes the remediation plan and adds cost without adding information. We will tell you that honestly.
What happens next
What we do with
your tool result.
If the tool says test, we coordinate with an independent industrial hygienist (we do not run tests ourselves, that would be a conflict of interest). They sample, they report, and you decide next steps based on the lab data.
If the tool says remediate, we send a technician for a free in-person estimate within 24 to 48 hours. Most jobs under 10 square feet are completed in a single day.
If the tool says monitor, we will send a follow-up reminder in 30 days. Many small moisture events resolve without intervention once the source is fixed and the area dries.
Questions on the result? Call (314) 947-3419 or message us.
Got the answer?
Call us. We will be on-site within 90 minutes most of the time.