Water Damage - Drying Concrete Floors
11315 Sunrise Gold Circle
Rancho Cordova, CA 95742
Water Damage - Drying concrete floors
After a water damage disaster, restoration professionals
like PuroClean Home Rescue are concerned with drying
everything as quickly as possible and restoring the
property to a pre-disaster condition. This includes
being aware of the unique properties of concrete, its
reaction to flood conditions, and the unique challenges
of drying that material.
When the walls and contents are dried after flooding
or other severe water damage, concrete areas are often
assumed to be dried as well. New floor coverings are
often installed right away. Within weeks, or perhaps
months, customers may complain that the newly installed
floor is defective. The real culprit, however, is not
the flooring, but most likely excessive moisture remaining
in the concrete and the condensation that can occur
because of the "dew point."
Dew point is the temperature at which water vapor in
the air begins to condense into water (or dew). As the
air cools, its ability to hold moisture is reduced.
If it continues to cool, eventually the air becomes
saturated with moisture and then condenses into water
droplets. Normally, a concrete floor is significantly
cooler than the rest of the room. Condensation will
therefore occur at the surface of the concrete long
before it happens elsewhere in the room. Such condensation
may form on the concrete even if the rest of the room,
walls, and contents have dried to their normal condition.
Many Contractors who are not restoration professionals
are unaware of this phenomenon, and move forward with
their restoration effort, including the installation
of floor coverings.
The damage-and-complaint scenario compounds when water-based
adhesives are applied over a damp concrete floor. As
moisture evaporates from the concrete, the water-based
adhesive absorbs it. This changes the moisture content
of the adhesive and prevents it from curing and becoming
fixed (or permanent). Since the adhesive fails to become
fixed, it will soften and move. Sometimes it appears
as bubbles or blisters in certain flooring materials.
When tile is applied, the adhesive may ooze or leak
out along the edges of the joints or seams. People may
believe that the flooring material is defective, but
the root cause is premature installation of the floor
The use of water-based adhesives versus solvent-based
has increased in recent years due to environmental regulations.
Water-based adhesives perform very well under the correct
conditions. However, when applied to a substrate with
higher-than-normal moisture content, the failure rate
It is important to contact restoration professionals
such as PuroClean when concrete has experienced any
type of water damage. Using the latest equipment and
procedures, they can determine when the concrete is
dry enough. The best method is to use a humidity chamber
or humidity box. These are either manufactured boxes
or bubbles of plastic taped to the floor.
The chamber traps the moisture released from the concrete,
eventually reaching equilibrium. The Contractor carefully
inserts a thermo-hygrometer into the chamber and measures
the equilibrium humidity. Because concrete is hydrophilic
(water-loving) this equilibrium humidity can often be
in the upper 60's. Any reading below 72% is sufficient
to install carpet or tile flooring. Wood floors should
have readings below 70%.
If the concrete floor needs additional drying, air
movement is the best way to hasten the process. Removal
of the boundary layer from the surface of the concrete
facilitates additional evaporation/drying of the concrete.
The room humidity levels will indicate whether a dehumidifier
is also needed. If the ambient humidity of the room
is below 50%, a dehumidifier is probably not needed,
but ongoing monitoring should be done to check for changes.
Please note that each of the respective trades associated
with installing floor coverings have established installation
standards. All of those standards require the installer
to determine that the subfloor (regardless of type)
is in a satisfactory condition to allow proper installation
of any floor covering.
Regardless of the circumstances - dealing with water
damage, fire/smoke damage, or mold remediation - call
your local PuroClean office, the Paramedics of Property
Damage™. For all property damage situations, these professionals
are standing by. They will mitigate the loss to prevent
further damage and will then provide restoration services
to return the property to a pre-loss condition as quickly
as possible. All PuroClean offices have well-trained
professional technicians who provide the latest state-of-the-science
services to all property damaged from water, fire, smoke,
mold, and other disasters.
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