Storm Water Got In? The 48 Hour Clock Starts Now

Maine has been running two kinds of weather at once this August, and the combination is putting water into buildings that stayed dry all summer. Most of the month has been hot, humid, and dry enough that the state slid back into drought. Then, every week or so, a storm cell shows up and dumps a violent amount of rain in under an hour. On August 13 a severe thunderstorm crossed Cumberland County with a 69 mph gust at the Portland Jetport, quarter size hail, torrential downpours, and power out for more than 10,000 customers. Storms rolled back through this Thursday, and forecasters at the Climate Prediction Center are calling for above normal precipitation through the end of the month.

Here is why that pattern matters for your basement. Drought ground sheds water instead of absorbing it. As of this week, roughly 926,800 Maine residents live in areas of drought, up 4.6 percent from the week before, with the worst of it running from Casco Bay to Penobscot Bay. When soil bakes for two months it gets crusty and tight, and clay soils shrink away from the foundation and leave a gap right against the concrete. A slow soaking rain would wet the top few inches and stop. The kind of cloudburst these storms deliver has nowhere to go. It sheets across the hard surface, finds the low spot at your foundation, and runs down that shrinkage gap like a funnel.

We see the results on the first calls after every one of these cells. Water lines on the slab that were not there in July. A finished basement where the carpet squishes in one corner and nowhere else. Window wells full to the sill because the gutter above them was packed with a summer of dry debris and dumped its whole roof section in one spot. The building did nothing wrong. The ground around it just stopped doing its share.

You have about two days, and that is usually enough

The number that matters is 24 to 48 hours. EPA’s guide to mold and moisture in the home says it plainly: if wet or damp materials are dried within 24 to 48 hours after the water event, in most cases mold will not grow. That window is the whole game. Storm water from a roof or a foundation wall is clean water. It did not arrive with a mold problem. The mold problem starts on day two or three, when a wet carpet pad sits under a dry looking carpet and nobody checks.

So if a storm put water in your building this week, this is the work for the next two days:

Get the bulk water out first. Wet vac, pump, towels, whatever you have. Standing water keeps feeding everything around it.

Get everything off the wet floor. Totes, furniture, cardboard. Cardboard is the first thing to grow and the easiest thing to throw away.

Check what wicked. Water climbs. Run your hand up the drywall above the visible water line. On these calls our moisture meter routinely reads wet six to twelve inches above where the stain stops. Pull the baseboard in the wet section. If the drywall behind it is soft or the paper facing is damp, that cavity needs to dry open, not sealed behind trim.

Move air and pull moisture at the same time. Fans alone push damp air around. A dehumidifier alone is slow. Together, with the basement windows shut, they can dry a room inside the window. Keep the space under 60 percent relative humidity while things dry.

Know what to keep and what to toss. EPA publishes a material by material water damage table. The short version: hard surfaces dry and clean up fine. Carpet can often be saved if you dry it fast, but soaked carpet pad is a discard almost every time, and soaked ceiling tiles are a discard every time.

When it stops being a homeowner job

Be honest with yourself on four points. If the water sat more than 48 hours before you found it, if it got inside wall or ceiling cavities, if you can already see growth covering more than a patch the size of a bath towel, or if this is the second time the same spot has been wet this season, drying alone is not the fix and it is time to have someone open it up and look. That is what our free assessment is for, and if remediation is actually needed, we have laid out what that costs in Maine so you are not guessing.

One more distinction that saves people money. Growth that fans out from a corner or runs in a stripe below a water line is a bulk water problem, the kind this storm pattern causes. Growth spread evenly across cool surfaces is condensation, a different problem we covered in our post on why dry summers still make wet basements. The fix for one does not fix the other.

If you own rental property, add ten minutes of paperwork to the list. Photograph the water, the date, and every step you take to dry the unit. Maine’s warranty of habitability now covers chronic moisture and mold conditions, and we walked through what the new rental mold law expects of landlords earlier this month. A documented fast response is exactly what that law wants to see.

The forecast says more of these downpours before the pattern breaks. If one of them finds its way into your building, do not wait for the smell. The clock is short, but it is long enough if you start the same day.