We had some water damage recently (leaky toilet supply line) that flooded an upstairs bedroom and the room immediately below it. We had all the drywall torn out in anticipation of rebuilding and had a mold test done. Despite the water being around for only a few hours before being discovered and removed, and there being no visible mold when the drywall was removed, elevated levels of mold spores were found in the air test. Specifically, Aspergillus/Penicillium and Syncephalastrum (12k and 1k spores, respectively, compared to 0 in the outside air).

The company wants several thousand dollars for remediation. I'd like to think there's a safe, reliable way for this to be done by the homeowner without spending a fortune. I remember countless homes in my neighborhood back during the last major hurricane having tons of visible mold and nobody hiring professionals to take care of it.

What's the best way to go about doing this ourselves?

1 Answer 1


A question - were there elevated spore levels in the rest of the house? It sounds like you disturbed something removing the old drywall. If that's the case you might be OK.

You need to identify the source. Once you've done that you can usually deal with the problem yourself.

The hard part is going to be identifying the source. Mould is usually caused by condensation on the walls, which in turn is caused by poor ventilation and insulation. So there's warm, damp air in the room which when it comes in contact with the cold wall forms condensation.

If there was no visible mould before removing the drywall, then you should be all right - but I'm not an expert so please don't quote me on that.

When you replace the drywall make sure you install adequate insulation and ventilation in the room and then perhaps test again for spores before decorating. If the levels are still high then you'll need to do more investigation.

  • The drywall was relatively new, there was no insulation in the walls, and we normally keep the thermostat at ~80 degrees in there because we're not using that room yet. That coupled with the walls being soaked for a few hours might answer it. What we're wondering now is what steps, besides removing the drywall and ventilating the room, can we take to eliminate the mold before rebuilding? Aug 22, 2010 at 14:17
  • @Mike - that might be enough if there was no evidence of mould before the leak. As I said, dry out the room, rebuild the wall with adequate insulation and then monitor for a few days before decorating. If there's a problem it should manifest itself quite quickly.
    – ChrisF
    Aug 22, 2010 at 15:04
  • Thanks. As an added precaution we left the windows open for a few days with fans running and we also blasted the room with Lysol (said on the can it killed several types of molds). Aug 25, 2010 at 2:54

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