TOP 10 MISTAKES HOMEOWNERS MAKE
1. Not realizing the significant impact a crawl space can have on the indoor air quality of a home
The crawl space is one of the most confusing and misunderstood areas in a building. Furthermore, because it is not easily accessible, it is also easily forgotten. However, it is one of areas within the building envelope that has the potential to most impact the air quality in the living area of the home. Because of a phenomenon called the stack effect, the air in your crawl space cycles into the living area of your home, taking with it any contaminants in the air of the crawl space. If you have a damp, moldy, unsealed crawl space, the chance that you have compromised indoor air quality in your home is high.
2. Failure to effectively moisture proof your crawl space
One of the most neglected and misunderstood areas of a building is the crawl space. As the saying goes, “out of sight, out of mind”. Taking the time to understand the impact moisture and mold in the crawl space can have on the integrity of the home can give you the tools you need to protect your home and health from the negative effects of mold and poor indoor air quality. We often receive calls well after a problem has begun, making the solution much more costly than the prevention would have been. Owners of new homes can take steps to prevent moisture and mold in the crawl space, saving them the cost of removing the mold and possibly having to correct even worse problems that may have developed because of chronic moisture intrusion. Owners of older homes can prevent further damage by having the crawl space cleaned and encapsulated now. If looking to purchase a home, a buyer should also have the crawl space inspected by a certified mold inspector (See #9 below). Addressing the crawl space issues now will prevent future damage, and protect what is probably the largest purchase you have made, your home.
3. Failure to adequately discharge roof rain water of homes with crawl spaces
In addition to encapsulating a crawl space, other steps should be taken to reduce the amount of water potentially entering the crawl space. One of those steps is to ensure that run-off from the roof is discharged 6 to 8 feet away from the home’s foundation for homes on a basement or crawl space. We see many homes with no roof gutters, or with gutters that discharge water within a foot or two of the foundation. This water has a very high potential for entering the crawl space, increasing the probability of mold.
4. Mistaking a plastic-lined crawl space floor for a sealed or encapsulated crawl space
Most people in the construction industry and knowledgeable homeowners realize the importance of a vapor barrier. In an attempt to address this issue, often 6 mil black plastic is installed. The black plastic sheeting is laid on the floor of the crawl space, sometimes below pea gravel. However, plastic sheeting is only minimally effective at keeping out moisture, mold, or odors from the crawl space. We see moisture and mold in homes of all ages that are thought to be protected from these problems by black plastic sheeting. Most plastic sheeting purchased at a home improvement store has no UV inhibitors, thus even short exposure to UV light will initiate a reaction that continues even after the plastic sheeting is no longer exposed to the sunlight. This plastic sheeting becomes brittle over time. When the plastic sheeting is under pea gravel, the breakdown process is accelerated, completely decomposing, but going undetected due to the layer of pea gravel. Our vapor barrier has UV inhibitors in it that keep it from breaking down, extending the life of the product.
5. Attempting to decrease crawl space moisture by increasing ventilation
Often the solution offered for a damp crawl space, by those in the building industry or even professionals not familiar with the newer building science research, is to increase ventilation. There are numerous companies that are proponents of this idea and who sell after-market items designed to increase the ventilation in a crawl space. This will not solve a crawl space moisture problem! New studies have shown that if you have a moisture problem in the crawl space, additional vents will only worsen the condition. Humid outside air entering the crawl space will condense on the cooler wood and duct work, worsening the moisture problem. See further information on this in the Crawl Space section (Click on the highlighted link text or click on Crawl Spaces in the vertical left-hand side navigation menu on this page).
6. Killing mold, but not removing it
There is a common misconception about mold and how to deal with it. Some contractors’ solution to a mold problem is to spray it with a disinfectant or sanitizing agent to kill the mold. While theoretically it has been “killed”, the mold is still there. If you have allergies or asthma, it doesn’t make any difference if it’s live or dead mold, they both will illicit an allergic or immune response. To remediate an environment, the mold MUST BE REMOVED. Encapsulating mold in place is not a good idea either. We have been in homes where the mold was left in place, but it was sprayed with a disinfecting or sanitizing agent to kill it, and then encapsulated with a mold inhibiting paint. While the mold may be covered up, it’s still there. This is not an industry approved method for dealing with moldy environments. While it is less costly up front, this method can cause problems years later from the potential risk the mold presents.
7. Exhausting dryer vents, bathroom vents, or kitchen hood vents into the crawl space or attic
Dryer vents, bathroom vents, or kitchen vent should be exhausted to the outside of the building. We often see these vents terminated in the crawl space or attic. This is adding moisture to the space and often results in raising the relative humidity to greater than 65%, facilitating the growth of mold. Unsuspecting homeowners can go for years unaware of this problem until an issue of moisture and mold arises.
8. Blocking soffit-vents when adding loose fill insulation to the attic
One of the easiest projects a homeowner can do themselves in terms of making their home more energy efficient is adding insulation to the attic. This is most easily accomplished by adding loose fill insulation, such as cellulose. A common mistake is to blow the insulation into the soffit vents, blocking them. This dramatically decreases the ventilation in the attic, increasing the risk of moisture accumulating in the attic. During the colder months, the moisture in the air can condense on the attic sheathing, facilitating mold growth. To keep the soffit vents from being blocked when adding insulation, install soffit-vent chutes or baffles to help maintain good attic ventilation.
9. Hiring an inspector untrained in mold detection to inspect your home or crawl space for mold
Hiring a mold professional is important when dealing with mold. We’ve seen home inspection reports not alerting the homeowner to serious problems in the crawl space pertaining to moisture intrusion and mold growth, and then there are inspection reports alerting the homeowner to mold when the mold is insignificant. In either situation, hiring a mold professional who is trained to recognize mold and who understands the effects of mold on indoor air quality will give you the information necessary for you to make educated choices regarding your crawl space. If you have allergies or asthma, or smell a musty odor in the home, have your home, especially the crawl space, inspected by a mold professional.
10. Not having a professional clean your air ducts
What do we mean by professional? Someone who has been trained to understand certain fundamental principles of cleaning air ducts. Cleaning air ducts is certainly not “rocket science”, but a few simple principles need to be followed and the person following them needs to be an individual of honesty. If not done carefully and properly, if corners are cut or shortcuts taken, air quality conditions can actually worsen in a home after air duct cleaning, creating more problems, especially for people with allergies or asthma.
11. Not having a professional conduct a mold inspection
More information coming soon.