In many areas, across this country, homes and businesses are constructed on foundations that create a space between the ground and the subfloor. This area is referred to as the crawl space. Why is it called a crawl space? You guessed it. In order for someone to move around within this area, he or she needs to crawl, because the vertical space is usually two to three feet from the ground to the sub-floor of the structure.
How can the crawl space impact the indoor environment of an occupied space?
Crawl spaces are notorious for harboring contaminants such as mold, bacteria, and high levels of moisture. Oh yeah, bugs too! Most crawlspaces are unconditioned, meaning no mechanical methods are being used to control temperature, humidity, or air pressure differentials. Plain and simple, there is no climate control. These contaminants can find their way into the occupied spaces of a structure via air currents moving through floor penetrations, cracks, and crevices. These penetrations exist to allow for electrical wiring, plumbing and duct-work to pass from the crawlspace and into the occupied spaces of the building. Unfortunately these gaps are often not sealed and allow for the unwanted air movement.
What are some steps we can take to reduce the potential of crawl space contaminants reaching our indoor environments?
- Seal the sub-floor penetrations to reduce the amount of “crawl space air” drafting into the occupied spaces. This can be accomplished by using caulk and expanding foam, in most cases.
- If you have a central ventilation system, make sure the duct system is sealed, preventing pressure differentials. This can also have a significant impact on your energy costs, by saving you money! There are energy conservation and indoor environmental companies that can measure leakage, locate the leaks, and seal ducts to prevent duct leakage. If you feel frisky you can also do this yourself with quality duct tape, duct mastic, and a theatrical fog generator. You will also want to make sure the insulation surrounding the duct-work is adequate and in good condition to reduce energy loss and prevent condensation from forming on the exterior of the ducts and surrounding structural surfaces.
- Keep the crawlspace dry by having a properly installed vapor barrier in place. The vapor barrier will keep water vapor in the ground, helping to prevent high moisture levels from occurring. High humidity can lead to condensation and therefore mold on structural materials.
- Proper drainage is important not only to steer water away from the crawlspace but to also protect the foundation from settling and cracking.
- Encapsulated crawlspaces can also be effective but they must be monitored for climate control. Monitoring of the space is usually accomplished by having a hygrometer or thermo-hygrometer installed. Climate control in a crawl space usually refers to humidity control, only. The humidity level is maintained by having a dehumidifier installed.
- Apply moisture control and/or anti-microbial coatings to the structural components. Moisture control coatings like KEFA will prevent condensation from forming by absorbing the water vapor when dew point is reached then releasing the water vapor when ambient conditions allow for evaporation. KEFA prevents enough surface water activity therefore inhibiting microbial growth. As a bonus KEFA will provide a thermal barrier and insulate the surface where it is applied and it works indefinitely.
Antimicrobial coatings manufactured by Fiberlock and Foster control microbes by leaching an antimicrobial agent to the surface of the coating where these chemicals can fend off microbes. These products offer protection guaranteed by the manufacturers for a period of five to ten years, normally.
Antimicrobial products like BactiBarrier® that use a Silane base to form covalent bond between the surface being protected and the antimicrobial are very effective. These types of products are considered “green” and very safe to use. The antimicrobial is referred to as a “molecular spear”. Microbes are attracted to the “spear” via an electrical charge. This is when the cellular membranes of microbes are penetrated and the microbes are destroyed. This type of antimicrobial also works indefinitely.
These are some of the most effective ways of protecting your indoor environment from your crawl space. But as you see we are also protecting the crawl space from microbial contamination when we use the aforementioned steps.
For over 20 years, we have been helping people who are working on improving indoor air quality with Indoor Environmental Surveys and Ventilation Systems Cleaning by providing high quality workmanship with unparalleled customer service to both residential and commercial customers. Our staff of professionals are dedicated to serving your specific needs from the moment you contact us until the completion of your remediation project. Visit our website or contact us today for more information or to schedule your mold remediation consultation.