April 24, 2009
Moisture
Meter Available
The NDSU Extension Services flood Web site provides information on flood
recovery, including a video on restoring flooded buildings and fact sheets on
topics such as cleaning your flooded or water-damaged home and drying out before
rebuilding. See Flood
Web Site
The Stark-Billings County Extension Office has a
moisture meter that people can borrow to determine if they adequately dried the
parts of their homes and other buildings that flooded before they start
rebuilding. There is a $100 deposit which is refunded when the meter is
returned.
People need to remember that cleanup, includes removing all porous materials
(such as carpet, drywall, fabric and ceiling tile), cleaning all nonporous
materials (such as metal and glass) and thorough drying, should be done soon,
but rebuilding needs to be delayed until moisture is no longer coming through
concrete in the basement and wood has dried to at least 15 percent moisture
content. Wood submerged in water will absorb a large amount of water, so drying
will take weeks.
A common problem with rebuilding too quickly is mold growth within closed
cavities, such as on the back of drywall (Sheetrock). Mold can trigger allergic
reactions, asthma episodes and other respiratory problems.
Air moves from within the wall cavity into the living space, so mold growth in
the wall will affect the living space. Air also will move from basements and
crawl spaces into the living space, so mold in these areas will affect people
living in the home. Living in an environment that contains mold is not healthy.
Wood moisture content should be at or below 15 percent to minimize the potential
for mold growth. Wood may not decay until exceeding a moisture content of about
20 percent, but mold growth is expected in wall cavities that contain wet wood.
Meters calibrated for measuring wood moisture content also can provide a
relative moisture measurement of other materials such as drywall. However, the
meters only measure moisture content; they do not determine if mold is present.
Meters are not available to detect mold growth.
Testing for mold requires sampling by a trained professional with special
equipment and evaluation by a technician with training in mold identification.
Its also very expensive.
If mold is visible or you detect a musty smell, remove the moldy material using
accepted procedures such as described in NDSU publication Remove
Mold for a Healthy Home.
