A. Discussion

Mold growth has become a serious issue in the modern climate over concerns with indoor air quality. Mold becomes a concern in the indoor living environment as mold releases spores and other byproducts into the air. Most health effects of mold are allergenic in nature and are temporary meaning that they will usually go away once the individual affected is removed from the “moldy” environment or the mold is removed from that environment. Most healthy adults are highly resilient to mold even when exposed to high levels of contamination. Mold is only a considered a concern by most when the concentrations found within the living environment exceed that of the outdoors at any given time or the speciation (type) is different within the home than outside. Several guidelines are now in place for the cleanup and treatment of mold including the EPA’s, (Indoor Air - "Mold Remediation in Schools and Commercial Buildings") and the New York City Department of Health (Mold Remediation Methods) among others. With these and other guidelines the primary concern is for the effective removal or cleaning of mold damaged items and building materials and the occupational safety for those workers performing the cleanup.

While these guidelines are essential for the remediator, they fall short of specific advice or guidance with regards to the non-living areas that surround the indoor environment. The primary intent of this essay is to address specifically the concerns present when mold is found in the crawl space of a home and to make recommendations for the reasonably appropriate handling of its removal and/or treatment. First, we will assert that the mold present in the crawl space is not likely to be as detrimental to the environment of the home as mold found in the living area. This is most likely true for the following reasons: the crawl space is an uninhabitable space that has been somewhat isolated from the home purposely; the crawl space is a utilitarian area created to allow for the quick and easy access to plumbing, ductwork and wiring as well as provide for a “softer” feel to the floor of the home and is not intended for the continual habitation of humans; the crawl space is inherently unclean as they are open to the ground to some extent, become a home for insects and rodents, and offer better conditions for mold growth even when constructed per local building codes. It is not a good idea to allow air to infiltrate from the crawl space into the home whether visible mold is present or not. Having stated this, it is prudent to isolate the crawl space from the interior of the home as much as possible. Mold and other contaminants that are present in the crawl space must travel through the ductwork or through cracks and crevices in the flooring to enter the living environment of the home. These “holes” should be sealed to the greatest extent possible using expandable foam insulation, caulking, the taping of ductwork joints, etc. Positive pressurization of crawl space should be avoided and corrected if present. It is better to attain a negative pressure in the crawl space relative to the home and maintain it if possible. This can be done by introducing fresh air into the home through the HVAC system or by pulling air from the crawl space with an exhaust fan.

B. Recommendations

With this information in mind, Indiana Mold Remediation offers the following service choices with regards to the treatment and/or cleanup of mold in/from these areas.

OPTION #1 – Fungicide treatment only, this is not mold removal (adequate for most situations to kill existing growth and minimize future growth). Based upon the fact that mold is not as likely to enter into the living environment from the crawl space and affect the home in the same manner as mold the living area, the application of an appropriate fungicide will kill existing mold and help to prevent it from growing in the future. The moisture source causing the mold to grow should be ascertained and corrected. This option should not be chosen if the crawl space is to be isolated and put under climate controls (i.e. air conditioned). Dead mold, while still capable of causing allergic reactions, will not continue to produce new colonies nor the byproducts of its life cycle. Most light surface growth that can de wiped away will be rinsed off as the fungicide is applied.

• A negative pressurization can be established at the customer’s request in the crawl space relative to the home can be established to aid in the prevention of cross contamination into the home.
• All visibly moldy insulation will be removed from the crawl space
• All breakthroughs and duct junctions can be sealed at the customer’s request using duct tape for the ducts and expandable foam or caulking for the breakthroughs.
• A fungicide labeled for such use will be applied by a licensed applicator per the product label. The fungicide used is labeled as a wood preservative and will help prevent future growth.

COST: (standard prices)

• Negative pressurization: $150.00 (most crawl spaces)
• Removal of insulation: $110.00 per hour plus $200.00 hauling fee for over 10 bags (most crawl spaces will require 2-3 hours of billable time to remove moldy insulation)
• Sealing of breakthroughs and duct junctions: $110.00 per hour (most crawl spaces will require 3-4 hours for this service)
• Fungicide application: $1.00 per square foot based on the footprint of the home.
• Average 1800 square foot crawl space would be around $2500.00 for the complete package

OPTION #2 – The second option is more encompassing and will physically remove the mold from the wooden structural members. Media blasting with soda (like sand blasting) is used to “sand” the mold from the wooden surfaces and remove it to its “root system.” This is the best option for seriously moldy crawl spaces where the minor transfer of air from the crawl into the home is still enough to spread contamination. This is also the best option if “mold removal” is desired. A thorough cleaning of the area is not warranted or recommended as it would be on the interior of the home and the moldy blast media is allowed to settle to the floor with the small amount of removed moldy wood. This in turn is covered with a new vapor barrier (plastic sheeting) to contain the mold to the ground where it is no longer an issue.

• A negative pressurization will established in the crawl space relative to the home can be established to aid in the prevention of cross contamination into the home.
• All visibly moldy insulation will be removed from the crawl space
• All breakthroughs and duct junctions will be sealed using duct tape for the ducts and expandable foam or caulking for the breakthroughs.
• All wooden structural surfaces will be blasted utilizing soda to remove visible mold. Fallout will be allowed to fall to the floor.
• A fungicide labeled for such use will be applied by a licensed applicator per the product label. The fungicide used is labeled as a wood preservative and will help prevent future growth.
• A new 6 mil plastic vapor barrier will be installed

COST: standard prices (a minimum may apply)

• Negative pressurization: included (most crawl spaces)
• Removal of insulation: $110.00 per hour plus $200.00 hauling fee for over 10 bags (most crawl spaces will require 2-3 hours of billable time to remove moldy insulation)
• Sealing of breakthroughs and duct junctions: $110.00 per hour (most crawl spaces will require 3-4 hours for this service)
• Cleaning of the Structural wood through media blasting: $2.00 per square foot.
• Fungicide application: $1.00 per square foot based on the footprint of the home.
• Application of a new vapor barrier: $.50 per square foot.
• Average 1800 square foot crawl space would be around $6850.00 for the complete package