Water leaks in a roof can be more than an annoyance if they produce conditions that allow mold growth.   If a leak has occurred, it is important to get it repaired as soon as possible to avoid continued water intrusion into a ceiling or wall system.  Even a slow or minor leak can result in serious mold growth conditions if left unchecked.  Sometimes leaks are not readily detected, resulting in conditions that support mold growth before we are aware of it.  When this happens, it may be the case that an odor or a respiratory difficulty is the first indication something is wrong.  Ignoring these indicators will only allow the situation to potentially develop into something worse.

There are a couple of ways to test for mold even if you can’t see it.  One of the easiest ways to determine if there really is a mold problem is to have the indoor air tested for mold spore levels and compare the results with outdoor air levels.  Normal indoor air should have similar levels and types of mold spores as found outdoors.  Hidden mold growth will often produce aerosolized mold spores that can be detected using air sampling cassettes.   This kind of testing provides solid evidence for the presence of hidden mold and an estimate of how serious the problem may be.  Depending on the results of this testing, further investigation may be warranted.

Another way to test for possible hidden mold without relying on the detection of aerosolized spores is to test the air for the chemical compounds that active mold growth produces.  These are called microbial volatile organic compounds or MVOC’s.  Even if the mold growth hasn’t released spores into the air, it’s metabolism will have released these chemical compounds into the air.  The test quantifies the total of these compounds in nanograms/liter.  A statistical correlation is applied to the likelihood of hidden mold depending on how much is detected.

Both tests have advantages and disadvantages, but cost is about the same.  We spoke about roof leaks in this scenario, but other kinds of leaks are applicable to the principles discussed above.  The take away should be don’t ignore what your nose or health is telling you.