How to get water damaged structures really dryby Carey Vermeulen
One of the most common mistakes made by restoration companies is simply assuming that the water-damaged structures they mitigate are dry without doing the proper inspection and analysis of moisture readings of the air, structural materials, and contents.
All too often, carpet cleaning specialists are brought into a water loss and do what they do best: Extract the water and set up drying equipment to dry the carpet.
A water loss usually results in the saturation of, but not limited to, flooring, subfloor, drywall, and possibly other structural materials.
Regardless of the building materials that are affected, water damage technicians may be overlooking additional areas that have absorbed moisture and may dry slower than the flooring.
Types of lossesOf course, our first responsibility is to identify safety and health issues, and secondarily, the category of water, as described in the IICRC S500-06 Standard & Reference Guide for Professional Water Damage Restoration.
Determining the category of water loss — 1, 2 or 3 — gives the technician direction in deciding which contents and structural materials need to be removed and discarded and which can be restored.
Then, it is critical that the technician identifies the degree of saturation. IICRC S500-06 designates four classes of water, based on the relative degree of saturation within the structure.
Knowing the class of water enables the restorer to distinguish and determine a plan for initial dehumidification and contents restoration.
The classes are defined as follows:
Class 1The first class includes the least amount of water, absorption, and evaporation. Only part of a room has been affected. No carpet or cushion is involved.
Class 2The second class includes a large amount of water, absorption, and evaporation affecting an entire room, including carpet and cushion. The water has wicked up the walls less than 24 inches. There is moisture remaining in structural materials.
Class 3The class has the greatest amount of water, absorption, and evaporation. Water may have originated from overhead. Ceilings, walls, insulation, carpet, cushion and subfloor in virtually the entire area are saturated.
Class 4This class identifies specialty drying situations,consisting of wet materials with very low permeability/porosity, such as hardwood flooring, concrete, subfloor, and areas with deep pockets of saturation.
Why determine category of loss?This type of information (determining category of loss) is an integral part of the documentation that restorers should collect on every job.
All too often, cleaners and restorers are brought into a class 2 or 3 water loss, do not identify the class of loss and proceed to restore the flooring by removing the carpet cushion, installing air movers, a dehumidifier, and checking three days later with a moisture sensor to verify the carpet is dry.
This can be a risky approach, with expensive consequences.
Leaving framing lumber, drywall, baseboard, base plates and subfloor wet will likely lead to the deterioration of the building material and provides a favorable environment for microbial growth.
Improperly identified category 2 or 3 losses can present an even higher risk of microbial activity due to the significant amount of contamination in it.
Determining the class of water gives the restorer an industry-accepted formula to calculate the initial
amount of dehumidification required to begin drying the structure with an efficient drying system.
This formula is based on the amount of moisture that will potentially evaporate from the affected areas and materials, as well as the amount of air movement that contributes to the drying process.
Based on the cubic volume of the affected area, the industry accepted predetermined factors, by “class of water, and type of dehumidifier” (the AHAM rating of a refrigerant dehumidifier, or the CFM output of a desiccant dehumidifier), the restorer will know how many dehumidifiers will be required.
The number of air movers is determined by the amount of wall perimeter. One air mover per 10-to-16 feet of wall perimeter is the industry accepted number.
The air movers are placed almost touching the wall at a 15 to 45 degree angle, depending on their output.
This makes initial inspection and moisture readings most critical when responding to a water loss.
Tools of the tradeThe use of moisture meters/sensors is an absolute must when evaluating a structure.
Thermo hygrometers provide the relative humidity and temperature of the air.
Penetrating moisture meters allow us to read through structural materials such as subfloor or hardwood flooring to determine moisture content at the surface, center and through to the bottom of the material.
Non-penetrating moisture meters are non-intrusive, and allow us to read through materials without causing damage, like ceramic tile or vinyl flooring.
Daily moisture readings should be recorded on a chart to make daily comparisons, monitor the drying progress, and assist in making adjustments to the type and amount of equipment being used.
Restorers should also determine a “dry standard.” This means taking moisture readings from similar materials that were not affected by the water intrusion, but are within the affected structure.
The dry standard then becomes the drying goal for the restorer to achieve.
When the drying goal is achieved, the structure can then be considered restored to normal moisture content.
Contents and structural materials should first be evaluated for restorability.
When contents and materials are not available for comparison within the structure, similar items, and their moisture content from similar environments in the immediate geographic area, should be used for setting a dry standard.
This creates drying goals for the project. Moisture content of affected materials and contents must equal that of the dry standard materials before they are considered dry.
Because of the potential for microbial growth within the structure and possible adverse health affects of the occupants, improperly dried structures can be a huge liability for the restorer.
The IICRC WRT and ASD certifications both offer training for the water damage restorer on the basics of extracting water and include the more complex issue of psychrometry and drying buildings. Go To http://www.advantagecleaningteam.com/ or http://www.janiservu.com/