Mold Inspecting Overview

Tools needed for mold inspecting:

• strong flashlight
• moisture meter - a pinless meter can be found for about $35-50 on-line. Pinless meters don’t make little perforations in drywall the way moisture meters with pins do.
• clear, transparent ¾” tape
• Ziplock bag
• notebook and pen
• permanent marker (or ballpoint pen)

Setting the stage:

"Mold is everywhere," so why get excited about mold? Yes, mold spores are everywhere. Good housekeeping continually removes mold particulates along with house dust. However, from a health standpoint, our concerns relate to mold growth.

Why is mold growth important? Because as mold grows, it makes spores which can float off into the air (as long there is a pathway for that), and it gives off gases, which also penetrate into room air. Both these can affect our health. There are other components of mold growth, too, which will be addressed later, specifically, microparticles and mycotoxins.

But first, let’s keep it simple:

Food and Water

Mold needs what we need to survive: food and water. To find mold growth, search where the food and water are, such as:

FOOD

• unfinished wood surfaces in the basement or crawlspace or in areas of water intrusion;
• vulnerable materials stored in a damp basement, such as furniture, books and papers, paintings, fabric, etc.;
• paper backing of drywall;
• sink cabinets;
• around toilets and showers, especially under base molding behind toilets and under base molding at the common wall with shower fixtures;
• bathroom ceilings, backs of old toilet tanks (not insulated well);
• leather shoes in a closet;
• furniture and other contents, etc.;
• dust and debris in the AC system and on AC coils.

WATER

• areas of condensation, such as
  • bathroom ceilings, window frames, well tank, hot/cold pipes, AC and dehumidifier coils and ductwork, etc.
  • at refrigerator gaskets, inside gaskets at doors of many front-loader washing machines
  
  
• areas with sustained elevated relative humidity
  • chronically damp environment
  • from flooding
  • inadequate attic ventilation with termination of bathroom plumbing exhaust in attic;
  
  
• water leak or overflow from plumbing, including at:
  • bathroom sinks, toilets, and showers;
  • kitchen sinks, dishwashers, and refrigerators and water filters;
  • air conditioner drainage pans;
  
  
• roof and flashing leaks, and ice dams


• water or water vapor from the outside, such as from:
  • below-grade spaces;
  • gutter or downspout issues;
  • land slope issues;
  • vegetation;
  • newer stucco, unsealed brick or other siding issues, etc.;
• rained on during construction

Follow the path of the water to find the mold, both visible and hidden.

• If, for example, there was water showing up at a bedroom ceiling from an ice dam, the water may have also penetrated into a wall cavity. Remediation would involve the bedroom ceiling and wall. Correct the conditions that made for the ice dam so it doesn’t happen again.


• If the washing machine failed, water might have penetrated into wall cavities, under flooring, and into the wall and ceiling cavities of the room below. This is a good reason not to put a washing machine on the second floor, unless there is an enclosure pan with a drain.

Why bother with mold that is in wall or ceiling cavities?

We remediate hidden mold, because the molds that typically grow in these cavity areas don’t require continued moisture to keep growing.

• Penicillium and Aspergillus can keep growing just from the relative humidity of unconditioned cavities (no air conditioning in the cavities).
• Because the mold structures are hidden, their growth will not be detected through room air or dust samples (or ERMI samples, to be discussed later).
• The health issues relate to mold gases seeping through cracks and outlets into the room air.

There is no inexpensive, sensitive test for mold gases. Even the more costly tests cannot tell you where the growth is. Save your money. The trick is to find and eliminate the sources, and then the gas production stops.

Use a moisture meter to find hidden moisture.

If there is, or was, water intrusion in an area with nutrient value for mold, that’s a place to look for mold growth. Like night follows day.

Moisture meters are effective but not guarantees of being able to reach the moisture. For example, perhaps the plywood sheathing in a wall cavity is wet but not the wall. You can only sample at the wall.

Mold growth may also be present in areas that formerly were wet but at present test dry.

Check:

• around plumbing
• inside sink cabinets by the plumbing
• at the base of toilets
• at the floor and walls by showers and around fixtures
• at the floor by washing machines, dishwashers, and refrigerators
• lower walls and exterior door sills/adjacent walls if there is risk for moisture intrusion from outside;
• ceiling with water staining;
• lower foundation walls and slab in basement to gauge dampness from outside and below

If you see discolorations that may be mold growth, try one of the following for a clue:

And what if you find elevated moisture?

-- Ask yourself the question, "Well, why wouldn't hidden mold be growing there? Is there food and water?"

-- You may have just found an area needing remediation.

If there is a leak, how would you prevent mold damage?

The key to avoiding mold growth is to remove wet materials before mold can grow.

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Before going on with more surface testing, let’s stop a minute and talk about Health Effects related to mold exposure. After that, we’ll progress to Testing Options for various aspects of mold testing. That section will circle us around to Tape Testing Instructions, where we pick up on the discussion above.

Or, go back to the Mold Topic Index.