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TREATING WATER DAMAGED CRAWLSPACES

DESCRIPTION OF PROBLEM

When rising water from river flooding enters structures and contaminates them from the ground up, professional restoration technicians must give detailed attention to the restoration of all affected areas. One of the most difficult areas to access and treat for microorganism suppression is the crawlspace under post-and-beam or platform-and-frame construction.

DESCRIPTION OF SOLUTIONS

The following guidelines are suggested for this phase of restoration work:

Provide forced air ventilation of the airspace underneath the structure, preferably with commercial air handling equipment (axial fans, air movers, smoke ejectors).

Ensure the building is structurally sound and electrical shock hazards have been eliminated.

Equip technicians working on or entering the structure with the following Personal Protective Equipment (PPE) as a minimum:

a. quarter or full-face respirator

b. protective clothing, rubber boots, chemical resistant gloves

c. eye protection (splash goggles)

d. hard hat or appropriate headgear

Remove any organic debris using rakes, shovels or other tools, deposited in the crawlspace by the flooding situation, as required. Fortunately, foundation walls usually preclude this requirement. Take special care to avoid rodents, snakes or other small animals which may have entered the crawlspace.

Remove wet or contaminated insulation from between floor joists or from around ducting, plumbing pipes, etc. Ductwork with internal sound/insulation liners must be replaced if direct contact with flood waters occurred. Plastic flex ductwork must be removed and replaced. Sheet metal ductwork must be evaluated for restoration feasibility.

Remove any plastic vapor barrier that inhibits evaporation of water from ground soil.

Apply a direct spray of 1to2% solution of sodium hypochloride (household chlorine bleach) to all surfaces. For decontamination of salvable structural components, application may be made through a HydroForce sprayer. Fill the one-gallon siphon feed container with 5.25% household bleach. The standard 1:9 dilution ratio will automatically provide a 1to2% concentration of chlorine solution when applied through a 8005 fan-shaped or appropriate conical-shaped spray jet.

Begin application from outside the structure if possible. A 6' - 19' extension with 90 degree elbow, with the spray jet affixed, enables technicians to cover most areas under the structure from the foundation vents without actually having to crawl under the structure.

Next, technicians, using appropriate PPE and with continuous forced air ventilation, may enter crawlspaces to saturate areas which could not be reached from the exterior vents. Care must be exercised to saturate all subflooring, joists, posts, beams, and foundation wall materials.

Maintain forced air ventilation following antimicrobial application in order to dry the crawlspace. Drying, along with nature's inherent ability to "decontaminate" ground soil, will render the crawlspace safe over time.

At present, new procedures using chlorinated foams are being evaluated and tested. It is anticipated this product may eliminate excess moisture while controlling microorganism contamination in inaccessible areas, including some crawlspaces.