Salvageable vs Non Salvageable Materials

Wet materials fall into either 2 categories, “salvageable” and “non salvageable”. What makes something “non salvageable” is when it can’t be returned to “pre-loss condition” after absorbing water. These materials can include but is not limited to: particle board/MDF (medium-density fiberboard) materials, drywall, baseboard, and carpet/ carpet pad. In the case of category 3 contamination (sewage, mold, bacteria, pathogens, etc.), every material that is affected besides concrete, hardwood framing, and subfloor (unless rotten or trapping moisture) gets removed (even tile since grout is porous), then cleaned, and dried before being repaired to pre-loss condition. Materials that commonly trap moisture include baseboards, wall/crawlspace insulation, sheet vinyl/linoleum flooring, and plywood underlayment under vinyl flooring. By not removing materials that trap moisture behind them, microbial growth can eat away at organic materials such as wood until they deteriorate and have to be replaced.

The Science of Drying

Once wet materials are exposed and disinfected, then the surface temperature of the wet materials needs to be raised higher than the ambient air temperature to cause the vapor pressure to force water to the surface of the materials. This is traditionally done using commercial refrigerant dehumidifiers to pull cold, wet air through the machine before condensing and purging the moisture, allowing hot, dry air to return to the room and heat up materials. In order to move that heat across materials and pickup the water vapor, commercial air movers are positioned in a particular way to properly circulate the air in the drying chamber to allow the air to cycle through the dehumidifier. This process can be aided with plastic containment to speed up the drying process and prevent cross-contamination. Depending on the amount of water and the affected materials, the drying equipment may need up to 24 hours to stabilize and create an environment that promotes drying (Relative humidity below 40% and a rise in air temperature.

Alternatively, excess moisture promotes mold growth that spreads spores through contact with the air, so putting air movement across visual growth is not recommended. If mold growth is present, the recommended action is to isolate with containment and setup negative air through an HEPA rated air filtration device inside the affected area to help clean the air and prevent cross-contamination. Once the affected materials are removed and the mold is remediated, then drying can begin.

After all materials in the drying chamber reach a moisture level of 16%, or within 2% variance of the structure’s dry standard, then drying is considered complete and the structure is ready for repairs. An average water mitigation takes between 3-5 days of drying after demo and costs between $2,000-$4,000 for a claim including 2-3 affected rooms, not including repairs (with the opportunity to rise significantly depending on what needs to be removed, how much equipment is set, and how long the equipment runs).

Mold

Mold “begins” as a spore that is often times brought inside structures from peoples clothing or air passing through windows and doors. These spores then land and wait for excess moisture to begin “activating” and eating any nearby organic material. The “activation” and sudden increase of spores is called “sporulation” and leads to the formation of “Hyphae”, which is a thread-like structure that eats organic material. When enough hyphae form and “clump up”, they create mycelium. As mycelium grow and compete with other molds strains and bacteria, they release Microbial Volatile Organic Compounds (MVOCs) as a form of biological warfare, that incidentally gives mold is musty, earthy odor and can lead to negative health effects such as: headaches, nasal irritation, dizziness, fatigue, and nausea.

Excess moisture can come in the form of direct saturation from a water source (think flooding and water leaks) or indirect saturation through humidity (water evaporating into the air). “Excessive” moisture levels that promote microbial growth in organic materials exceed the structure’s dry standard by more than 2%, or if the inside relative humidity increases over 60%. Moisture from humidity can move through air ducting by the HVAC system and saturate the organic materials in the ducting from lack of cleaning, which can then lead to MVOCs that are spread throughout the structure wherever the HVAC system leads. Having the thermostat switched to “auto” helps the system maintain proper humidity levels by activating at specific conditions and condensing excess moisture from the air, specifically in summer months.

Additionally, mold is broken into 3 categories when it comes to remediation: Category 1 is “normal” interior spore counts compared to the exterior (not visible), category 2 is the sporulation process (likely not visible), and category 3 is mold growth that is visible to the naked eye. Mold surface and air sampling is most useful when mold is category 1 and 2 since it lets you identify problem areas and compare counts to later tests to check remediation efficacy. To ensure mold remediation’s are done properly, it is recommended to get surface and air sample testing done before work starts, again after demo and cleaning, then additionally as many times it takes until the tests show interior spore counts at a satisfactory level compared to exterior spore counts.