2026-07-10 · Dave Kessler · 4 min read
After a Leak or Flood in a York House
Speed beats products. The colony has not started if you are still moving water.
Hour by hour
The clock is in how fast mold grows. If you remember nothing else: water out, materials opened up, dehumidifier on, no box fan blowing into the kitchen.
Storm water versus a pipe
Water that came in from the yard may be muddy and is often an insurance argument. A supply-line break is cleaner and often a clearer claim. Either way, document it. Do not store wet photos only on a phone that dies in the same flood.
Rebuilding
Do not close the wall the same weekend. Let the framing dry to a meter reading someone will put in writing. Then use details that can get wet again without a secret paper face — especially on below-grade walls.
Questions people also ask
+Should I run the radon fan during dry-out?
+Can I stay in the house?
These pages are homeowner education from Radon Mitigation of York, written by Dave Kessler. They are not a medical diagnosis, a species identification, or an insurance determination. Color does not tell you which mold you have. If someone in the house is sick, talk to a physician. EPA's homeowner guidance treats roughly 10 square feet as the line where many people stop DIY cleanup and call a remediation crew — sooner if sewage, HVAC, or anyone immunocompromised is involved. We are a radon and basement crew. When we are already under a York house we will tell you what we see and what we would do in our own place. We do not pretend a radon fan is a mold remedy.