Hot Spots For Mold

 

Damp Basements and Crawlspaces

Musty, mildew odors are a sure signal that a basement is too moist. Look for patches of mold-like growths on the walls, ceiling, and floor. Also, mold is commonly found on cardboard boxes, wallboard, behind walls,
and on wood studs (see our section
on Basement Mold ).

 

Crawlspaces in this area are fraught with moisture problems caused by high water tables, poor drainage of rainwater, insufficient grading away from the home, condensation from HVAC ductwork and pipes, and excess humidity. The problem is that this moisture will lead to mold growth, and /or insect (termites) and vermin infestations if left unchecked. Since the air in your crawlspace reaches your living space every day (up to 50% of the air on the first floor comes from the crawlspace), mold spores and any mycotoxins will invade your home as well. See our section on Crawlspace Mold for more information.

 

Kitchens and Bathrooms

Common spots where we find mold colonies in a kitchen are behind or under the sink, above the stove or around the venting system, behind cabinets, inside cabinets, below or behind the dishwasher, and on the ceiling. Leaks are common around the kitchen sink either from the water supply side or the drain not working properly. Normally, slow leaks are the worst in that they are sometimes not found for days or weeks and mold will almost certainly be well established. Dishwashers are hot spots, not only for the possibility of leaks, but for the “steam” they create which easily condenses on the ceiling or cabinets. Make sure your exhaust vents are working properly over the stove and that they are not venting into the attic!

 

Bathrooms are obvious problem spots by their very nature. Look for leaks under the sink, around the toilet, in the shower and bathtub. It’s not uncommon to find bathroom water invading lower level areas causing multiple mold problems; on the ceiling, in the rafters, behind walls, etc. We have seen problems caused by consistent shower splash, either from curtains or improperly installed or closed doors. Just a little water added every day to the same area will often be “wicked” into surrounding porous material such as wood and wallboard causing major problems over time. Just as in the kitchen, make sure that your vent system is working to exhaust the steamy air and make sure it’s not venting into the attic.

 

Attics

The problem we normally find with attics is poor ventilation stemming from improper design or non-working or occluded vents. Poor ventilation means that the humidity rising from your home or from the environment does not escape and will condense when the attic cools off in the evening. Condensation will also occur on un-insulated pipes or HVAC ductwork. Of course, as pointed out in the prior two sections, having bathroom, kitchen, or dryer vents exhausting into the attic is problematic. Please see our section on Attic Mold for more information.

 

Washrooms

Over the years almost all of us are going to experience a water problem (or flood) stemming from the washing machine. Sometimes the automatic turnoff fails when the machine is filling, sometimes the high pressure water hose in the back of the machine bursts and often the drain pipe starts to leak or slips out of the drain pipe. Just as in other areas, often it is the slow leaks that you don’t discover for a while that cause the most mold damage. Some of the most toxic of molds (Stachybotrys) thrive in very wet conditions and take up to a week to propagate.

Clothes dryers can also cause moisture problems when not vented properly. Dryer vents should exhaust to the outside of your home, not into the attic or another room. Also, clogged dryer vents will cause your unit to not function properly and will increase the humidity in your home (this also is a fire hazard, so please check your dryer
vents frequently).

 

Renovated Rooms

Why would a recently renovated area be cause for concern? There are countless horror stories of water or waste pipes being hit with nails or screws by an unsuspecting do-it-yourselfer or professional alike. Perhaps the worst is when just a “pinhole” leak is caused. There have been famous cases where a pinhole leak behind a wall went undiscovered for months and the extensive mold growth caused major and very expensive remediation work to be done. So, please be careful when piercing a wall with sharp instruments, whether you’re remodeling or just hanging and picture!