Some definitions

Fungi is the scientific term for the organism that we know generically as mold and mildew. There may be in excess of one million species of fungi. Allergens are molds that cause allergic reactions in the same way you can react to allergens from cats. Mycotoxins are toxins produced by certain fungi that may be toxic and harmfull to humans and animals.

The basic ingredient for Mold

For mold to exist you need moisture. The moisture may come from plumbing leaks, outside water coming into the house or from moisture condensation.

Why is mold now a problem?

The downside over the last 40 years to saving energy by building tighter homes with better insulation and the general use of air conditioning and certain HVAC systems, has been to reduce the air flow between the home and the outside. This reduction in air flow has helped to allow inside moisture to remain which in turn has provided the basic ingredient for mold to grow. Tighter homes have a complicated effect of depressurization, pressurization, humidity and dew point temperature which helped moisture to enter the home or to condense with resulting mold growth. Take a look at the links on my home page to read about this in detail. It is the law of Unintended Results at work.

What is the risk?

It is accepted that some fungi species can certainly be allergenic and an irritant to humans and animals. Those who suffer from asthma are more sensitive to an allergic reaction from mold. Other species of mold can apparently cause serious infections especially in people with a compromised immune system. There is a question of whether fungi can cause disease such as cancer but there is literature to support this.

The risk depends on the susceptibility of the person being exposed, the amount, extent and type of the exposure (inhaled, skin contract, ingested) and the type of fungi.

Research is on going (and conflicting). Right now there is little government or scientific standards or guidelines. However, some molds are known to more often produce indoor mycotoxins: Fusariu, penicillium, aspergillus veriscolor and stachybotrys chartarum. A fungi concentration indoors that is significantly higher than the outdoor ratio is an indication of an indoor source of mold for that species as is finding a mold species indoors that is not found generally outdoors.

Homeowners should assume that mold must be controlled.

Determining a mold problem

The first line of defense is your own visual and olfactory inspection of the home. While there are do-it-yourself test kits available to the homeowner, testing and a real understanding of the results really requires an expert. First Alert has a mold detection kit (Cat. MT1) that is mailed in for results. Pro-Lab has a kit (M0109) that will indicate mold within 48 hours but then you must send the petri dish sample in to identify the mold.

If you have concerns (or the whole house inspection shows concerns) than find a qualified expert to assess the problem with a visible and olfactory inspection and sampling such as source (sterile swab or surface stripping), sample analysis (laboratory culture) or air sampling of both the inside house air and outdoor air. The expert may examine inside walls with fiberoptic equipment through a small opening or use a moisture meter.

Removal of the mold

First of all, it will do little good to remove the mold, if the conditions that created the mold (i.e. water leakage) remains so that the mold returns. Therefore, correcting a mold problem involves not only mold removal but also will include repair or changes that allowed the moisture for mold growth in the first place.

Second, the homeowner should be carefull before undertaking any removal other than what would qualify as a small area and where the mold resulted from the presence of clean water. The United States EPA defines a small area as 10 square feet or less and still recommends the use of goggles, gloves and a N-95 respirator. Cleaning mold can make the situation worse by releasing spores into the air. Consider the use of a product called Concrobium to seal the mold spores before cleaning and removal. There are other products such as OxiOut and OxiShield.  Carefully read all manufacturer's directions for use and applicability of the product. Go to the EPA publication website under Interesting Links on my home page and carefully read all EPA recommendations before undertaking any removal.

The best approach is that the manner of mold removal  should be determined and carried out by an expert. Correction may require removal with biocides or antimicrobial chemicals or the safe removal of porous materials such a wallboard or even non-porous materials such as ductwork.

Preventing mold

Prevent unwanted moisture and you will go along way in preventing mold growth. The most obvious source of unwanted moisture is leaky plumbing and water entering from the outside due to lack of maintenance (i.e. roof, gutters) or failure of the structure to prevent infiltration (i.e. through the foundation.)

You also need to control moisture from condensation. This is a complicated topic that depends on your climate as well as air barriers, vapor barriers and even your wall coverings. Read thoroughly or consult an expert but a rule of thumb is to shoot for an indoor relative humidity below 60 percent.

Building tightness versus the benefits of energy savings is another complicated topic that you will have to study and/or consult with an expert. However, properly managing air pressure and airflow will help to prevent mold.

Contract Inspection paragraphs

Most standard mold inspection paragraphs in real estate contracts are inadequate to protect a home buyer. Most mold inspection paragraphs involves the buyer in an extensive process of determining a mold problem, determining the process of removal, determining repairs to prevent recurrence and determining how the costs will be paid. During this process the buyer is rushed to a closing date and fought all the way by the sellers and sometimes attorneys and/or realtors. You want the absolute right to be satisfied the mold problem is corrected or to walk away from a serious mold problem without liability and return of your earnest money. A buyer cannot rely on standard inspection paragraphs to accomplish this.