Oxidative Mold Remediation in Colorado A WHITE PAPER BY RICHARD CARPENTER, WRT, ASD, AMRT In the past few years, oxidative remediation protocols have gradually become established for professional mold remediators. This white paper documents one such project in the mountains of Southwest Colorado, under adverse weather conditions, to show the efficacy of such products, and the best practices and proper procedures for their use. 11/6/14 - Inspected crawlspace at 1928 CR 500 in Vallecito Colorado for potential mold issue. Heavy rains have resulted in trapped moisture and microbial growth in crawlspace. Substructure wood is wet at between 20-40% throughout, and various species of mold are also present on the affected wood (joists/subfloor) throughout crawlspace. ATP readings were 1600-5000 (very high) and the crawlspace is currently Condition 3 (active mold growth and high levels of spores present) Inspection Photos and ATP test photos. Photos 1-6 Photo 1.
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Photo 6 A quote was prepared by UltraSteam and accepted by the contractor responsible for the build. Initial tape lift testing was independently performed by Jeremy Baier of Central Flood Management prior to our arrival, and work commenced 11/12/14. Remediation Record: 11/12/14 - Established negative air pressure within crawlspace using a HEPA-filtered NAM to prevent cross-contamination and provide ventilation during remediation efforts. (Photo 7)
Photo 7 - HEPA vacuumed all affected wood with wirebrush attachments to remove the un-adhered surface growth and mold spores. (Photo 8) Photo 8
- Applied Concrobium broad-spectrum disinfectant using foamer to kill mold growth prior to drying process. (Photo 9) Photo 9 - Set up Dragon X2 drying furnace and airmovers to bring the wood back to an acceptable moisture level (12-15%) (Photos 10 & 11) This type of heatassisted drying has two benefits: faster drying of substructure wood in adverse weather conditions (it was actually snowing through part of the job, and overnight lows were in the teens and twenties) while maintaining negative pressure, and also getting the wood warm enough (>60 degrees F.) to ensure good performance of the mold stain remover.
Photo 10 Photo 11 11/13/14 Moisture check showed wood moisture dropping but still elevated at 17-22 points. Repositioned airmovers.
11/14/14 Moisture check down below 16% throughout. (Photos 12 & 13) Photo 12 Photo 13 11/14/14 cont Removed airmovers and performed ATP tests in the control area (Photos 14 & 15) ATP testing after initial vacuuming and drying showed substantial reduction in microbial activity, but was still unacceptably high. Wood surface temp was at 78 degrees F. Photo 14 Photo 15
- Applied Concrobium Mold Stain Remover to all affected wood. (Photo 16) Photo 16 - Scrubbed with nylon brush and allowed to work overnight. (Photo 17) Dragon continued to heat crawlspace during this phase to maintain wood surface temperature above 60 degrees F. Photo 17
11/15/14 - Performed final HEPA vacuuming with nylon brushes to remove mold fragments, spores, etc. (Photos 18 & 19) Note the drastic difference in the appearance of the wood! Photo 18 Photo 19
A vapor barrier was installed over the soil to help prevent future mold issues. Finally, Concrobium Mold Control (residual fungistat) was applied to all crawlspace wood to help prevent future growth. (Photo 20) Photo 20 Final ATP tests were well within acceptable range (less than 50 on luminometer) (Photos 21 & 22) Photo 21 Photo 22
Cosmetically, the wood appears as though nothing had ever happened. No residual tannic staining remains, (Photo 23) although in some cases on other jobs where the wood has been affected for many years we have seen tannic staining that could not be removed even through sanding or sodablasting, without removing too much of the wood to be practical. Photo 23 Jeremy Baier of Central Flood Management visited the site again after we had completed work and left. He took tape lift samples and they were sent in for independent lab analysis. Final clearance testing found normal fungal ecology. Two samples, in fact, had no mold whatsoever. The lab report is attached.
Conclusions: Oxidative remediation does in fact work, not only in the lab, but in the real world of mitigation and remediation, when performed in accordance with the IICRC S520 Mold Remediation Standard and IICRC S500 Water Damage Standard. Projects should be performed and supervised at all times by an IICRC Certified AMRT. Product-Specific Notes: We mix the MSR with water at 100 degrees, using a drill-driven paint mixer. (Photo 24) It is important to dissolve the MSR powder completely, and to allow the necessary generation time for the peracetic acid to form, and then to apply immediately over the course of the next hour or two. Light scrubbing with a nylon brush produces better results particularly on heavily stained wood, or where the predominant staining is quite dark. Also important is that the wood surface temperature be at or over 60 degrees Fahrenheit, for best cosmetic results. Photo 24
Appropriate PPE is required for application of the MSR, including a chemicalresistant suit, heavy gloves and full-face respirator with OVR cartridges. Note the use of this in Photos 9 & 16. We use a solvent-resistant heavy-duty sprayer to apply the MSR, and have found that it works best to have a teejet filter assembly to catch any small undissolved particles and prevent tip clogging during the MSR application process. (Photo 25) Also important is to clean sprayer promptly and thoroughly after each use. Photo 25
Respectfully Submitted, Richard Carpenter UltraSteam Professional Cleaning and Restoration