New Public Enemy #1: Mold

Dear Pat,
We'll be going on the market soon, so we want to get our basement in selling shape. We took your advice, and got our furnace cleaned and tested. We cleared everything away from the walls, and the dehumidifier is running full blast. But the basement still smells musty, and the corners show mildew stains. It's discouraging. How far should we go with this?
---Dampened spirits

Dear Damp,
First let's look at our Rogue's Gallery of home menaces over the past thirty years: formaldehyde, lead, radon, asbestos-each has taken its turn as the condition most likely to destroy health and real estate value. Yet none of these will give a buyer pause today (what ever happened to radon tests?), largely because common sense lifestyle practices can usually avoid the dangers posed, and when necessary, abatement or containment is fairly straightforward. One particularly insidious menace, mold, has largely managed to escape official scrutiny up to now, even though it probably accounts for more actual health problems than all the others combined.

But it's a new day, and high time, in my opinion, for mold to land atop this public enemies list. The new state-mandated Seller's Disclosure form devotes a full page to water intrusion and mold growth. It lists many sources of moisture, both exterior and interior (not enough space to list here-but some would surprise you), and it suggests that buyers may want to have the property inspected for moisture problems before entering into a purchase agreement, especially if they observe staining or musty odors on the property.

So what does this mean for you, Damp? Just as you were smart to head off furnace questions by getting it ready in advance, so you would be wise to eliminate mold sources now, to avoid problems with a potential buyer later.

First, do your best to stop water intrusion from outside: install good gutters and downspouts with adequate extenders, landscape to promote drainage away from the house, and if necessary, drain tile the basement. Next, make sure you're not adding moisture (from plants, humidifier, long showers, etc.) to be trapped inside due to inadequate ventilation.
   
I've discovered, to my dismay, that most people in south Minneapolis never open their basement windows, thus forgoing the cheapest and easiest way of alleviating mold and musty odors. It's the first thing I ask sellers to do, and they are usually reluctant because of security, or they have no screens, or the windows are stuck tight (no surprise, in a basement with tropical humidity levels!). This is why I'm such a big proponent of glass block windows with vents: around $200 for an average window, they offer light, security, ventilation-and they can pay for themselves by saving the use of a dehumidifier.

Finally, try an ionizer machine to kill existing mold and mildew, even behind walls. I've had astonishing results in my own home, and reports of huge improvement from other people as well. Prices vary; mine cost about $300. So the short answer to your question, Damp: go as far as your wallet will let you--mold needs to be taken seriously.