Pressurization: Negative Pressure
1. Sanding &/or Wire Brushing:
Method:
Conduct sanding using a random orbit sander, or a similar tool.
Utilize 60-80 grit sandpaper for effective material removal.
Employ wire brushing for detailed cleaning in specific areas.
Procedure:
Work from the highest point to the floor within each room designated in the remediation plan.
2. Chemical Treatment:
Alternative to Mechanical Removal:
As an alternative to sanding and wire brushing, chemical treatments, such as hydrogen peroxide, may be used.
These treatments aim to clean and extract the root structure of mold from wood or other porous materials.
Application:
Apply chemical treatments using an airless sprayer for even coverage.
Mild agitation can enhance the effectiveness of the chemical process.
3. Media Blasting:
Specialized Technique:
Baking soda or dry ice blasting may be required for specific project conditions.
However, these methods are rarely employed in contemporary remediation due to logistical complexities and the significant mess they generate.
Detailed/Thorough Vacuuming:
Pressurization: Negative Pressure
Comprehensive Cleaning:
The primary containment area must undergo thorough vacuuming, encompassing all surfaces from top to bottom, including the containment plastic itself.
Source Removal techniques & HEPA vacuuming can not be performed at the same time within the same containment.
Debris made airborne during source removal activities will contaminate freshly cleaned surfaces.
Surface-Specific Tools:
Ceilings, floors, and smoothly finished walls should be vacuumed using a large surface tool.
Exposed framing should be vacuumed with a detail/brush tool to ensure thorough cleaning of intricate areas.
Crevices and hard-to-reach areas should be addressed using a wire brush and a crevice tool.
Systematic Approach:
Vacuuming should be conducted from the highest point to the floor within each room specified in the remediation plan, ensuring a systematic and thorough cleaning process.
Equipment placed on the project will require shifting to allow vacuuming beneath these items.
Additional care must be taken when moving this equipment that the ducting for the AFDs or Dehumidifiers used does not create a mess that will potentially recontaminate the area you're working in.
Air Duct Cleaning should be scheduled towards the beginning of the HEPA vacuuming sequence. This way if the duct cleaning makes a mess, it won't generally require extensive work to correct it.
Wet Wiping:
Pressurization: Neutral Pressure
Dust-Free Environment: The entire structure should now be a dust-free environment, achieved through thorough vacuuming and cleaning.
Wet Wiping & the initial HEPA vacuuming can not be performed at the same time within the same containment. Follow up HEPA vacuuming may be conducted while wet wiping within the same containment. However, care must be taken to not make a mess.
Neutral Air Pressure: Negative air pressure is no longer required. The AFDs should be converted to neutral pressure.
At this stage, negative pressure can potentially draw more contaminated material into the containment.
Neutral pressure allows the AFD to process the air to very low particle counts as it's not drawing in particulate from outside.
Wet WIping:
The entire structure must be cleaned with detergent and warm water.
Use of detail brushes is typically required to agitate areas that the towel can't reach.
Only unused towels should enter the detergent water.
The towels should be folded & refolded to expose a new "cleaner" area of the towel, until that towel has no folds left.
Returning dirty towels to the detergent water will contaminate the water rendering it less effective.
Used towels should be placed in a trash bag to be laundered with bleach before being boxed for reuse.
This includes:
Windows including their jambs.
Door & window casings.
Framing members
Plumbing & electrical wiring.
All Equipment including their cords.
The containment plastic itself.
Extension cords.
Essentially, everything within the contained area.
The interior of the structure should achieve "operating room level" cleanliness.
Wet wiping should be conducted from the highest point to the floor of each room, following the remediation plan.
HEPA Sandwich:
Definition: The HEPA sandwich is a cleaning process involving:
HEPA vacuuming a surface.
Wiping the surface with detergent and water.
Followed by an additional HEPA vacuuming.
Necessity:
If thorough vacuuming has been performed, a follow-up vacuuming should not be required.
Ineffective vacuuming is typically revealed during the wet wiping stage.
Areas with ineffective vacuuming will require re-vacuuming and re-wiping.
Concept:
Cleaning agents applied to surfaces that have penetrated into the surface, will allow material within the pores to be lifted to the surface requiring vacuuming to remove.
Pail and Bag Cleaning Process:
Individual Cleaning Pails:
Each employee, or pair of employees in a given area should have their own pail with warm water and detergent.
Only clean, quarter-folded towels should be placed in the detergent solution.
Towel Management:
Once a towel has been folded to the point where no clean sides remain, it should be placed in a preferably clear bag with other soiled towels.
Reintroducing a dirty towel into the pail reduces the cleaning solution's effectiveness & cools the water.
Towel Laundering:
Soiled towels should be taken to the office and washed on a heavy duty setting with laundry detergent, hot water, and chlorine bleach.
Dried towels should be boxed in labeled plastic totes for future project use.
Spray Foam Sealing Process:
Addressing Difficult-to-Clean Areas:
Certain areas may not allow for effective cleaning, such as:
Gaps between studs.
Framing around windows and doors.
Dirt associated with drains under tubs and showers entering the slab.
Any other "gap" that may cause issues.
Adding spray foam creates an effective barrier between potential contamination & the air that'll be tested.
This prevents potential contamination from affecting air samples during clearance testing.