ICS Magazine

A Look at the Latest Tools for Wall and Cavity Drying

January 25, 2013
cavity drying hardwood
In the early days of my carpet cleaning career, responding to a call for water damage restoration meant we would extract water from the carpet and perhaps place one or two air movers blowing under the carpet. Little or no thought was given to the moisture inside the wall cavity or to other wet surfaces.
Fast forward three decades. 
Times change and progress happens. Professional restorers have a number of excellent tools to help us locate and remove moisture from all parts of a building. These tools have saved many a wall or hardwood floor from the dumpster. While eliminating the need for much structural repair, these tools are saving the insurance companies money and making the job of restorer easier and more profitable.

Equipment is available that will deliver high-pressure air into wet wall cavities to speed up drying. Some wall drying systems can also vacuum air out of walls. This feature is useful when there is concern that mold or other micro-organisms inside the walls might be blown to other parts of the structure. This can be accomplished with a minimum of disruption. Nozzles that inject air into the walls require easily repairable holes as small as a quarter inch.
Other wall drying systems use adapters to direct air flow from centrifugal air movers or axial fans into wall cavities. Other tools adapt to fans, air scrubbers, dehumidifiers or other equipment with 5-24 outlets.
If you have not kept abreast of all the products on the market, you might be surprised at the special abilities of some units. Consider the versatile unit that can deliver high volumes of air into 10 linear feet of wall. They are flexible enough to even bend around corners! As many as five of these units can be connected in series using air supplied by just one air mover. When the job is done, the drying unit can be folded up to fit in a box just larger than a gallon jug.
Rather working only with one specific fan, these special drying units can be attached to any standard air mover, axial fan and even the heat exchange boxes of heat-based drying systems.
This equipment will dry more than walls. Use them to direct air under cabinets, above ceilings and into other tight spaces. Many wall drying units, including the one described above, can also be used to accelerate the drying of hardwood floors by directing air underneath. A restoration job in a rec center dramatically demonstrated this ability.
The hardwood was located in a large gym, installed over two layers of plywood with plastic and rubber disks underneath (to cushion the pounding feet of basketball players), all over a concrete floor. A flood had left all layers of wood wet and puddles of water in the space below the wood. 
After three weeks of drying efforts where the in-house staff blew air over the surface of the wood, the moisture content of the floor was still way above normal and there was still standing water below the floor. Using the system discussed above, air from a heat-based drying system was directed under the hardwood and into the space below. The surface of the floor was covered with vacuum matts attached to vacuum units. These were spaced appropriately and then the flooded section was tented with additional warm air being directed in. Within three days, moisture readings were back to normal, the cupping of the wood had subsided and the floor was put in use without any need to refinish.
The restorer had invited me on this job. We initially told the rec center manager that we expected the floor would need to be refinished when dry. Frankly, I was surprised that when the cupping subsided they were able to resume use of the floor immediately. It’s always better to under-promise and over-perform. The manager was very happy with the results. 
Water damage restoration in the 21st century has advanced a great deal from drying in 1980. Cleaners and restorers of 2013 will benefit greatly by equipping themselves to take advantage of the latest tools.