How to handle mold?

February 10, 2008 9:38 PM

So, how can mold/mildew grow without moisture?

So, as a followup to my previous question.

I tried the Damp-Rid for 3-4 days, and it didn't collect any water.

I ran the ozone machine in the house for about 2 days, and it killed all of the mildew/mold smell. Then I turned my dishwasher (right next to the sink) on: the smell came back. I took my dishwasher door apart, cloroxed all parts, and then ran the ozone machine for another day. Problem solved!

Except, I ran my sink (specifically, the hot water) ... and all of a sudden, the smell re-emerged. So, I ripped out the base of the cabinets, and the drywall, and found the hot water line (and the cold water line).... NO LEAKS, whatsoever.

But, everything was effectively covered in the black mildew/mold thing. So, the questions:

1) How can the mold be growing without a water source? And, why does it 'reactivate' because of the hot water pipes nearby?

2) So, at this point, if I have to call a mold remediation company, what are they gonna do? Are they just gonna rip out my cabinets and charge me to do so?

posted by The Giant Squid to home & garden (11 comments total)

A pipe that carries cold water will collect dew. No leak is necessary.
posted by Steven C. Den Beste at 9:40 PM on February 10

SCDB: It's PVC pipe, and, I've never really seen it collect moisture. Moreover, touching the pipes directly, I don't feel any wetness of any sort.
posted by The Giant Squid at 9:54 PM on February 10

It doesn't matter what it's made of, and it doesn't have to be wet all the time.
posted by Steven C. Den Beste at 10:24 PM on February 10

I'm not a mold expert by any means, but I've had to sit through a few lectures on mold, buildings and health in an aerobiology class. It was emphasized often that once the spores show up, it's usually pretty difficult to totally remove them (the physical force with which they can penetrate surfaces is rather strong) unless you physically hack them out (ie not just scrub with bleach). That could be a reason why it returned in spite of no visible signs of moisture.
posted by mandymanwasregistered at 10:57 PM on February 10

Baton Rouge LA has a really high humidity rating. My memory of LA is that mold grew everywhere. My armchair non professional thoughts are to halt mold killing measures, and refocus on drying. Maybe some professional insulation that seals the basement and a dehumidifier. Or, move to Arizona. ;-)
posted by Blingo at 11:04 PM on February 10

There's moisture everywhere. Everywhere! It's like it's in the air or something. :)

Maybe see if you can get a jar of silica gel and pour some out on a saucer that you keep in there every few months.
posted by aeschenkarnos at 11:16 PM on February 10

Chlorine dioxide mostly harmless at concentrations that murder mold.
posted by hortense at 1:21 AM on February 11

you said there was a leak previously. it's possible that your house is still wet from that leak, especially since you live in Baton Rouge. you could get a small dehumidifier and run it under your sink and see if that helps. definitely wipe down everything with bleach. but if that leak was going for a long time, the water may have really soaked into things. you'll have to really tear out all around where it was leaking and just take out the wet wood/ drywall/ insulation/ vermin nests/ etc...

it's also quite possible that you still have water leaking and just haven't found it yet. until you are totally certain you've fixed the leak, there's nothing you can do or a mold remediation company can do about the mold except clean it up with bleach.
posted by geos at 4:09 AM on February 11

This is probably what you don't want to hear, but you should consider consulting with remediation experts. Mold spores can deeply embed themselves into porus material and can stay dormant for years. To address the condensation issue the least you could do to slow down the issue is to invest in a dehumidifier.
posted by samsara at 6:16 AM on February 11

If you want to at least try something yourself before you call in the experts.... consider MoldControl 500 from Scotts. It's a "kit" with basically a hydrogen peroxide base, some surficants (shampoo) and a propellent. The kit is identical to the decontamination foam that they cleaned the anthrax out of those DC buildings a few years ago. It can help somewhat with more porus surfaces.

Hydrogen peroxide by itself can also work if the area is temporarily dry enough. Might be worth a try before you call in the expensive professionals.
posted by answergrape at 8:26 AM on February 11 [1 favorite]

Well.

I found the source!

I ripped out enough cabinets, sheetrock, and masonry, to discover:
The previous owner left a piece of galvanized sewer pipe uncapped after they remodeled the place in 2000.

Large loads poured down the sink will backflow out of that pipe (hence the fact that we only smell it after running the sink or dishwasher), reigniting all of the mold in the walls.

I capped the galvanized pipe, and the mold smell has already started declining!
posted by The Giant Squid at 7:04 AM on February 14