Water damage mitigations are very complex. Each loss has different needs depending on source of loss, areas affected, age and layout of the home or business, how long things have been wet, the amount of water involved, whether there is any biological growth such as mold, etc. So how do the different pieces of equipment work together to dry your home or business? 

After standing water has been removed from the structure, there are two main processes involved in drying a structure: dehumidification and air movement. When excess water enters an enclosed area, evaporation rapidly increases the amount of water vapor in the air.  The type of equipment used to dry the air is dehumidifiers, which fall into two main classifications.  Refrigerant dehumidifiers pull in the moist air, then cool it to cause excess moisture to condense out of the air.  This moisture is then pumped out of the building.  Your air conditioner does the same thing on a smaller scale.  The difference is that the dehumidifier, after cooling the moist air, reheats it and pumps it back into the room.  The heat generated during the drying process works in your favor because warm air in the room can hold more moisture as water evaporates from wet surfaces. 

Another type of dehumidifier is called a desiccant. This device uses a material that absorbs moisture from the air passing through the unit, then pushes the dry air back into the room.  A desiccant dehumidifier can produce much dryer air than a refrigerant, and at lower temperatures.  The desiccant material is similar to the little packets found wrapped with some shipped articles.  You probably have seen the little packets labeled “DO NOT EAT.”  They are designed to keep packed articles dry during storage.  In the machine, the saturated desiccant material is heated and moist air is pumped outside so that more airborne moisture can be captured.  A desiccant dehumidifier can dry air so much that wet materials can be damaged by over-drying, so the equipment must be monitored carefully. 

After the air is dehumidified, it is passed over damp surfaces to speed up the natural evaporation process.  A wet material such as a wood floor or sheet rock wall produces a “boundary layer” of very humid air at its surface.  This boundary layer must be removed so that more moisture can evaporate.  The machines used in this process are called air movers.  Air movers are not “fans.”  A fan has blades like a propeller and is designed to move air around.  Specialized air movers, sometimes called blowers, are designed to cause laminar airflow.  Think of it as a moving sheet of air covering a wide surface area which pushes aside the boundary layer to allow faster evaporation.  The process can be likened to moving a dry sponge across a wet countertop.  The sponge absorbs water, the counter is dried, and the wet sponge is squeezed dry in the sink. 

The best way to get water from wet materials into the air depends on what materials are wet and what is in the environment.  Saturated wood, for example, takes longer to dry than sheet rock.  Also, not every material should be returned to the same moisture content.  A trained technician will test the moisture content of similar materials in dry areas to determine the proper goal for drying, or the “dry standard” for each material.  Air movers are directed at the areas with the highest moisture readings first to begin a steady consistent drying process. As the structure dries, the air movers are adjusted around the affected area to maximize the evaporation process.  In some circumstances, however, there may be reasons to change procedures.  Where there is biological growth like mold, for instance, air movers could spread mold to other areas. In those cases, the technician may not be able to use air movers and can use only dehumidifiers to remove water vapor.  Water evaporation then would be much slower.  In some situations, where mold is growing in a localized area and can be contained, air movers can be used to speed the drying process. As stated above, water damage mitigations are complex, so trained professionals are essential for the safety of everyone in a water-damaged home or business. 

Another piece of equipment commonly used in water mitigation is the air scrubber. This is a high-grade air filter that is used to remove particulates from the air during heavy demolition activities, such as removing drywall or carpet. It is also used when biological growth such as mold is found so that any spores that become dislodged will be cleaned from the air instead of floating around in the air. Air scrubbers are usually multi-filter devices allowing the air to flow through increasingly fine filters which catch and remove increasingly smaller particulates. The goal is to clean the smallest particles out of the air without clogging fine filters with larger particles. 

Sometimes a mitigation technician needs to open an enclosed cavity such as a wall, under or behind cabinets, or the area between the ceiling of one level and the floor of the level above it. The purpose of opening these cavities is to allow airflow in pockets of trapped moisture. It is very important to dry out these areas, since trapped moisture will almost certainly grow mold if it is not dried out and treated accordingly. Other areas, such as padding under carpet or laminate flooring, can also have trapped moisture. Depending on the type of water that caused the loss, occasionally those materials can be dried in place by lifting cover and replacing it when the area is dry. In most cases, however, due to the level of contamination from the material getting wet, the materials must be removed and replaced during repairs after drying. 

Whether to dry with air movement or not, whether to open a cavity or not for drying, whether to remove an affected material or dry in place, are all decisions that should be made by trained professionals. Their decisions are based on industry guidelines, professional experience, and regular contact with your insurance company to ensure that your water damage mitigation dries the affected area completely while still complying with your policy guidelines. Knowing what to do and how to use professional equipment properly is the key to a successful water damage mitigation.