Mold prevention around Hartfordin older and flood-touched buildings

Standard mold prevention assumes clean water that you can dry in place. Near the outlet channel and Catherine Creek, it may not be that simple. Water that crossed a road or a yard carries silt and whatever else it has met, and silt left on a floor or under a house holds moisture and gives mold something to feed on. Washington's flood guidance says lake and river flood water counts as black water, and the EPA's flood guidance says highly absorbent materials that cannot be cleaned and dried belong in the trash. ^[5]

So here, the order of work is: remove mud and soaked porous materials, wash the hard surfaces, and then dry. Running fans before this just moves dust and contamination around, and if you can already see mold, the EPA says to wait on fans and dehumidifiers until it has been gently cleaned. ^[1] Our main mold prevention page has more about the drying side. Everett Herald reports show this is not hypothetical: the outlet channel overtopped Hartford Drive in the record rain of November 2021.

Older buildings have features that can both help and hurt. Solid old lumber tends to dry well if it was sound. Plaster holds water longer than drywall, and its lath behind can stay damp for a surprisingly long time. Layers of old flooring, wallpaper and paneling hide moisture and mold. Washington's Department of Health says that a mold smell can mean growth behind wallpaper, inside walls or ceilings, or beneath carpet.

Before you disturb any of this, ask about testing for asbestos and lead. Older paint, flooring and plaster can contain them, and scraping or cutting can raise dust. If you are cleaning surfaces, avoid dry brushing or sanding them. Older homes may also have little or no wall insulation, so moisture may behave differently from what a contractor sees in a newer home. Ask for readings at several heights on a wall, not only near the floor.

Sheds and shops often take on water and then get forgotten, while all the attention is on the house. Cardboard, old fabric, seed, tools with wooden handles and stored furniture all make good mold food. It is worth emptying these buildings after a flood and letting them air out in the next dry spell. Throw out what is soaked and cannot be cleaned, and photograph anything of value first. Take care with stored chemicals and fuel, because containers may have leaked.

If you run a business from the site, think about the moisture level in stored stock. Paper goods and packaging can grow mold quickly, and you may be able to save more by moving dry stock out of the damp room right away. Your insurer may want to see what was damaged, so keep a list and take photos.

The EPA says people with asthma or weak immune systems ought to avoid both moldy sites and flood cleanup, and that children and pregnant people ought to leave flood cleanup to others. This is worth taking seriously in older buildings, which may also have lead and asbestos. If someone becomes unwell during or after cleanup, tell a doctor what they were exposed to.

Washington's Department of Health advises hiring a professional if mold involves sewage or is out of sight, and both are likely after flood water reaches a septic or drain line. It also notes that the state has no specific certification requirements for mold or water damage work. Check that any contractor is licensed, bonded and insured, using the Washington L&I Verify tool, and ask them how they will find and stop the moisture. ^[7]