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Drying Tips Page 4

7.0) Water (drying): (page 4 of 5)

7.24.a) Wall Access Holes: When water and moisture are trapped between walls, access holes could be required to dry wall cavities with airmovers or injection drying systems.

Access holes in walls should be performed with care so not to disturb the walls’ finish and should be penetrated along the lower and upper perimeter of the rooms wall or walls. 

When necessary, baseboards and casing should be removed as outlined in Section 6.26 and 6.26.a.

The use of perforated holes throughout a wall should be done as a last resort. Perforated hole throughout a wall or destructive demolition could be considered when water loss conditions are severe and all other means have been evaluated.

7.24.b) Ceiling Access Holes: The drying of ceiling cavities could be accomplished by drilling access holes along the upper perimeter of a ceiling where the ceiling meets the wall and access holes should not be larger than 3/8" to 1/2" in diameter.

Special care should be taken on the direction of ceiling joists for cross ventilation.  Ceiling joist and floor joist patterns can be determined by pre-inspecting the basement floor joists and/or attic ceiling trusses.

Airmovers using mini-turbovent or injection drying (pressure) could be used when drying ceiling cavities.

Excess water within cavities should be drained before using air-moving systems. 

7.24.c) Cabinet Access Holes: Water and moisture can become trapped under cabinets, between cabinet backs and walls, creating microbiological growth and rotting. 

Some base cabinets have toe kicks, which could be vinyl or wood. 

After the cabinetry baseboard is removed, access holes could be drilled into the toe kick and airmovers with mini-turbovents or injection drying can be used to dry the cabinets cavity.  

When the integrity of the cabinetry is jeopardized due to swelling or warping, or when mold (fungi) had formed on particle board, the cabinet should be replaced.  Minor mold formation on plywood or solid wood based cabinets can be cleaned and sanded-out (underside and backside), and the non-finished areas can be coated with a microbial inhibiter paint.

Before the remediation of a cabinet is performed, cost vs. value should be evaluated.

7.25) Documents and Magnetic Media: Books, documents, blueprints, diskettes, tapes, etc. are easily damaged or destroyed by high temperatures, water and high humidity. 

Loss sites, where books, documents, blueprints and magnetic media are exposed to water or humidity should receive immediate attention.  This should include the removal of items from wet and humid areas to a neutral area or site for dehumidification, or put into deep freeze.

Temperature, humidity and dew point readings should be taken and monitored in areas where books, documents and magnetic media are stored. 

Humidity levels of 45% or higher should be considered dangerous to books, and a temperature of 65º F or lower should be maintained when books and documents are wet.  The ideal constant environment for books is 55º to 70º F with a relative humidity of 40% to 55%.

Books and documents can develop mold within 24 hours, and when inspecting books for possible mold growth, never open books more than 180 degrees.

When handling books, never remove a book from a shelf by pulling down at the top of the books spine with ones’ index finger.  This can cause the spine to tear, the proper handling is to grasp the book by its sides.

Objects found in or left in books, such as flowers, book markers, photographs, newspaper clippings, money, etc. should be removed and stored in a labeled baggy and turned over to the property owner.

Books, documents and blueprints that have been stored in basements and attics could have pre-existing conditions such as, mold, mildew odors or vermin damage.  Vermin’s such as silverfish, roaches, and bookworms will tunnel through a books’ paper and its adhesive possibly leaving droppings.

When moving or storing damaged books, a cardboard bankers box sized at 15" x 20" x 10" is recommended, while blueprints that are rolled should be transported in PVC pipe or a drawing tube. 

Blueprints that are stored in drawing drawers and documents stored in filing cabinets should be transported in their respective cabinet drawers when wet. Hanging blueprints and maps should be placed onto a heavy cardboard box and interleave cardboard between each set.

It is recommended that books, documents and blueprints be frozen within 48 hours after a water loss to prevent mold growth.

Wet documents, maps, blueprints, etc. should not be separated while wet, and the separation of wet items should be done after they have dried. 

Vacuum freeze drying is recommended when drying documents, books, blueprints, etc.

7.28) Electronic Restoration: Electronic equipment should be cleaned by a competent person. 

Operating manuals and manufacturers should be consulted before disassembly begins, and technicians should refer to serial and model numbers when consulting the manufacturer.  Line diagrams should be drawn of all inter-working components, and photos at varying angles should be taken before and during disassembly.  

Outer casing: Wet dirt, mud, and silt deposits should be removed with care using a soft terry towel and mild detergents so not to scratch its surface.  Hard (dry) dirt, mud and silt deposits should be removed using regulated air or vacuuming, then cleaned with a mild detergent using a soft terry towel.

Interior components:  Could be cleaned using dry ice (CO₂), soda ash, ultrasonic or low pressure washing.  Detergents should be non-ionic and all components should be rinsed of all detergent residues with clean mineral free water.  Electronic equipment manufactured with integrated circuits, semiconductors or ultrasonic welds should not be cleaned using the ultrasonic method unless pre-approved by the equipment manufacturer.  

Electrical and mechanical connections: Electrical connectors and wires could be cleaned using mild detergent.  Mechanical connectors, piping, tubing, etc. should be cleaned using a non- ionic cleaner, then rinsed with clean mineral free water.

The cleaning of electronic equipment should conform with ASTM and IEEE standards.

7.29) Artwork: Artwork; originals or prints should receive prompt attention when affected by water, and an art conservation firm should be consulted promptly. 

Artwork should be moved to a neutral area when conditions are that of high humidity, even when the artwork is not wet or moist.

When artwork is wet, it should be laid flat (not upright) on a dry surface to prevent water from running and forming to the bottom of the frame and causing absorption damage, and this should be done in an area where it will not be damaged by foot traffic.

When artwork is wet it should not be wiped dry, this is to avoid possible separation of its paints from the canvas.

When a chip of paint or frame is loose, the paint chip or piece of frame should be placed in a labeled envelope or baggy and attached to its framework.

When artwork has sustained damages, it should be crated, packaged and shipped promptly to an art conservation company, when in doubt about handling, temporary storage, crating, packaging, etc., an art conservationist should be consulted.  

Trapped Water in Modular Home Flooring System
Source: William Yobe & Associates
Photo 7-31

7.30) Electrical Systems: Electrical wire, equipment, apparatus, devices, fixtures, etc., when exposed to water, flooding, humidity or sewage, should be cleaned and reconditioned per the “Guidelines for Handling Water Damaged Electrical Equipment” set forth by the National Electrical Manufacturers Association (NEMA).

Clean water should not harm some electrical wiring or some equipment when the circuitry is off.  While the age of the equipment, type of equipment and exposure time to water or moisture, and degree of flooding should be considered when reconditioning electrical wiring, equipment, apparatus, devices, fixtures, etc.

Motor windings, terminal connections, insulation, and apparatus can fail prematurely, be destroyed, cause electrocution if energized while wet, or when having a high moisture content. 

Mud, silt, dirt, dust, corrosion deposits, water and moisture on or within electrical equipment could require disassembly of the electrical equipment or apparatus.  Before the disassembly, repair or cleaning of electrical equipment begins, the manufacturer of the equipment or apparatus should be consulted to prevent further damage or hazards.  Moreover, only competent persons should perform the cleaning, reconditioning and testing of electrical wiring, equipment, apparatus, etc.   

Electrical equipment, insulation and apparatus should be thoroughly dried before being re-energized, and electrical equipment, insulation and apparatus should be tested using appropriate means before being re-energized.

Insulating materials found on some motors and apparatus should be cleaned using an approved solvent, while some synthetic resins used as insulating materials are not suitable with some solvents.  Moreover, insulating compounds should be identified and confirmed before using solvents.

7.30.a) Electrical Systems Cleaning: Electrical systems; wiring, equipment and apparatus could be cleaned using clean water with a neutral based detergent, steam, regulated air pressure, dry ice blasting (CO₂), non-abrasive soda ash blasting, or low-pressure washing when approved by the manufacturer. 

When cleaning electrical equipment or apparatus with water or steam, the blasting pressure should not exceed the manufacturers’ recommendations.

After cleaning, all residuals should be removed.

Devices: Receptacles and switches (i.e., GFCI) shall be replaced when submerged in water.

Fixtures: Only light fixtures rated as submersible should be cleaned for re-use when submerged in water, while all others shall be replaced.

Insulation cleaning: Wiring (cable) insulation could be cleaned using an approved solvent or water and detergents, while cable or wire containing polypropylene, paper, etc., such as; type NM-B cable, or cables listed for dry locations should be replaced when submerged in water.  In addition, cables or wire with metallic components can corrode and fail prematurely after water submersion.

Terminations: Electrical terminations, wire nuts, lugs, bugs, strips, etc. could fail or cause shock hazard when exposed to corrosion, silt, etc.  

Equipment cleaning: Motors, Motor Control Centers (MCC), panels, disconnect switches, etc. should be cleaned and reconditioned per NEMA recommendations, and the reconditioning should be performed in a clean and controlled environment.      

Apparatus cleaning: Electrical apparatus, as defined in this manual, should mean; any electrical equipment that produces or alters voltage, be it low, line, or high voltage.  Dry-type transformers, and dry type control circuit transformers should be replaced when infiltrated with flood water, while liquid filled transformers and cast-resin transformers could be reconditioned.

Fuses and Breakers: Fuses and circuit breakers when submerged in flood water shall be replaced. 

Instrument cleaning: Electrical equipment and apparatus could have instruments to monitor voltage, amperage, watts, demand, etc.  When instruments or meters have been submerged or suffered moisture damages, they should be returned to the manufacturer for reconditioning or replaced.

Bearings and mechanical components: Motors have bearings that could be sleeve or ball. Bearings can be pre-lubricated or require continual lubrication and greasing.  Heat and corrosive moistures can deteriorate the bearings lubrication, and bearings should be inspected for corrosion (rust/pitting/abrasions) before and after cleaning.  Bearings should be cleaned using manufacturers approved solvent and should never be allowed to soak at the bottom of a cleaning tank.  They should be suspended via wire or basket, and toxic, harsh and abrasive solvents should be avoided.  Bearings should be oiled after cleaning and before testing.  Once cleaned, bearings should be protected from further contamination. Shafts, gears, belts, etc., should also be inspected for mud, silt, rust and pitting.

Ferrous metal cleaning: Electrical equipment and apparatus are generally enclosed within ferrous metal cabinets and raceway, and they can be cleaned using water with mild to moderate detergents, or with dry ice (CO₂) or soda ash.

Stored Electrical Equipment: Electrical equipment, apparatus, wire, devices, fixtures, etc. in-storage should be inspected, tested, cleaned, restored or replaced when submerged in flood water.  Electrical equipment, apparatus, wire, devices, fixtures, etc. when in-storage and after exposed to flood water should be tagged as unusable until tested, cleaned, restored or replaced.

Before mitigation or restoration procedures are attempted or performed on electrical equipment, apparatus, etc. the electrical power should be turned off and lock out and tagging procedures set forth by OSHA should apply. 

7.30.b) Electrical System Drying: Drying temperatures, time limits and methods would depend on the material being dried, and equipment manufacturers should be consulted before drying begins. 

External and internal drying is the two basic methods available.  Vacuum (internal) drying chambers is the most efficient and thorough method.  When drying electrical equipment, the drying procedures recommended by ASTM and IEEE should apply.

7.30.c) Electrical System Testing: Electrical equipment, wiring and apparatus should be tested before being put back into service after suffering flood,  water or moisture damage.

There are multiple meters available for testing electrical systems:

Meg-Ohm Meter: used on wire insulation and motor windings to test the insulation-resistance, which will vary depending upon moisture, cleanliness, etc.

Dielectric Strength Tester: used to test the voltage stress of the electrical apparatus insulation and the moisture content strength of transformer oils 

Volt/Ohm Multi-Meter: used to read AC and DC voltage and resistance.

Amp Meter: used to read and record the rate of flow of electricity, a/k/a ampere or amperage

Thermal Imaging: used to determine hot spots or weakness  in insulation, and moisture vapor within insulation, conduits, etc.

Electrical system testing should be performed by a competent person, and testing should conform with ASTM, IEEE and NEMA standards.

7.31) Modular Homes: Due to the construction make-up of modular homes, vapor barriers on the underside of the sub-floor can trap water from above as shown in Photo 7-31.

When mitigating water losses in modular homes, the guidelines described in Sections 6.36 and 6.36.a should apply.