The Mold Problem
After an annual termite inspection, one of our customers in Winterville, GA called us to inspect her crawl space for moisture and mold. Upon inspection, we found that her crawl space had excess moisture, which was sustaining the mold growing on the floor insulation, floor joists, and subfloor.
The moisture in the crawl space originated from water seeping through the foundation along the back of the house. The grade sloped toward the house rather than away from it, so rain water naturally flowed toward the base of the home. Although a partial vapor barrier was in place, it did not cover all of the dirt in the crawl space, which left a significant amount of dirt exposed. Water had accumulated both under and on top of the vapor barrier.
Before we began the remediation process, the homeowner informed us that she preferred that we not use any toxic products or products that would produce strong or offensive odors.
The Remediation Plan
The first step toward removing the mold was correcting the source of moisture. To keep the water out, the grading in the backyard needed to slope away from the house. We recommended a general contractor that regraded the yard, excavated and waterproofed the foundation and installed French drains to capture and divert any water that does make it to the foundation.
Once the client corrected the source of accumulating moisture, we determined that to remove the mold and provide long-term mold prevention, we would take the following steps:
- Remove the floor insulation.
- Soda blast all floor joists and subfloor.
- Coat all floor joists and subfloor with a mold inhibiting coating.
- Install a new vapor barrier.
- Fog the crawl space with a mold inhibitor.
We created a two-day timeline to carry out the mold remediation in accordance with the client’s preference for natural products.
The Removal Process
When we arrived on site, we began by removing and bagging all of the floor insulation. We then used a soda blaster to clean the floor joists and subfloor. We used soda blasting in this case because it leaves an extremely clean, stain-free surface. The blasting media, baking soda, is non-toxic, and the structure of the home allowed easy access for the blasting equipment.
We used a Buster Blaster 100 soda blaster powered by a trailer-mounted, diesel-fueled air compressor. The crawl space was 1,220 square feet, which required four 50-pound bags of soda blast media.
After blasting was completed and we removed the residual baking soda from all of the surfaces, we sprayed the floor joists and subfloor with a mold inhibiting coating. We chose the EPA-registered Foster® Full DefenseTM Fungicidal Protective Coating (40-25) because it kills residual mold and provides long-term fungicidal activity.
Foster® Full DefenseTM provides a clean, white finish on coated surfaces, which results in a brighter crawl space, with spotless surfaces that the homeowner can see clearly. We applied a total of five gallons of the product using an airless sprayer.
We started day two by preparing the floor of the crawl space for the new vapor barrier. We removed the old vapor barrier, dug out all of the rocks and debris, raked the surface smooth, and leveled out several piles of dirt that had collected in the corners.
We then constructed the new vapor barrier over the newly smoothed dirt surface. From foundation wall to foundation wall, we installed 6-mil clear polyethylene sheeting. To keep all moisture out, we wrapped the sheeting around the base of the foundation piers, overlapped seams by at least 2 feet, and sealed the seams with spray adhesive and tape. To keep the vapor barrier in place, we inserted 6-inch galvanized spikes and washers every 5 feet along the perimeter and seams.
For the final step, we fogged the crawl space with Concrobium® Mold Control to kill any remaining airborne mold spores and to provide one more layer of protection against future mold growth.
We were able to completely eliminate the crawl space mold while meeting the homeowner’s need for non-toxic, low or no odor products:
- The soda blast media consists of ordinary baking soda.
- Foster® Full DefenseTM is a low odor, low VOC, water-based coating.
- Concrobium® Mold Control is a non-toxic product that produces no odor and no VOCs.
This project resulted in a dry, bright and clean crawl space, free of mold growth and protected for years to come with a solid vapor barrier and a full fungicidal coating. Our customer was satisfied with both the results and our remediation process. Contact us today to find out how we can solve your mold problems!