University of Wisconsin-Extension
Walls
must be dry from the inside out before restoration, repainting
or recovering can begin. Even when walls feel dry to the touch,
the material inside the wall may be wet. Drying the inside
of the walls may take weeks or even months. The total drying
time will depend partially on the amount of dry air that can
circulate through the studding and different wall materials.
Plaster
and paneling can often be saved, but you still need to get
air circulating in the wall cavities to dry the studs and
sills. Wallboard soaked by dirty floodwater will need to be
replaced. If the wallboard was damaged by clean rainwater,
consider cutting a 4- to 12-inch-high section from the bottom
and top of walls. This will create a "chimney effect"
to speed up drying time. A reciprocating saw with a metal
cutting blade works well for this task, but use only the tip
of the blade and watch out for pipes, ductwork and wiring.
- Remove
drywall, laminated paneling and plaster at least to the
flood level. Warping above the water level often occurs
with drywall and paneling, so more may need to be removed.
- Plaster
walls can sometimes be adequately drained by removing the
baseboard and breaking out plaster and lath at the bottom
of the wall. Later the baseboard can cover the opening.
- Some
paneling may be salvaged if allowed to dry slowly. Remove
the baseboard from paneled walls and pry off the individual
sheets. Prop them against the wall to dry. Don't allow them
to dry in sunlight, which may cause warping.
- Remove
vinyl-covered wallpaper. It will restrict drying within
flood-damaged walls.
- Water-soaked
insulation should be removed and replaced. It can hold water
for months, causing odor and decay problems. While wet it
has little insulation value.
- Consider
wainscoting as a restoration option if flooding is no higher
than 3 feet above the floor.
Do not
attempt to repair plaster until walls and inner walls (studding
and insulation) are completely dry. If walls were flooded
extensively, you may need to wait four to six weeks, or even
several months, before attempting repairs.
Drywall
compound is the preferred method for patching plaster. It
comes in a variety of types with different drying times, shrinkage
characteristics and consistencies. Read labels to select the
type you need.
- Dry
wall cavities from the inside if possible. (See previous
section.)
- Remove
small section of siding to check conditions on the reverse
side. If crevasses are filled with silt, remove siding to
water level and clean. Silt left in crevasses will trap
moisture, causing mold, decay and peeling paint.
- Check
for cracked or warped siding. If only a few boards are warped
or cracked, replace them individually.
Sheathing
is the material between studding and finish siding. Depending
upon the type of sheathing, replacement may or may not be
necessary.
- Wooden
boards should dry slowly and some will warp. Re-nail warped
areas after they dry. Replace those that are too badly warped
to salvage.
- Sheathing
board is usually absorbent and difficult to dry. Replace
any that is disintegrating or separating.
- Plywood
will probably separate and must be replaced. Marine plywood
will not warp or separate, but is generally considered too
expensive to use in residential construction unless the
building is subject to frequent flooding.
Additional resources:
Your county family living agent, your local emergency government office, the American Red Cross, the Federal Emergency Management Agency
Related publications:
"Removing Water From the Building Materials of a Water-Damaged Home," University of Wisconsin-Extension, Madison, 1994.
"Repairing Your Flooded Home," American Red Cross/Federal Emergency Management Agency, 1992.
TIPS on Repairing or Rebuilding Your Disaster-Damaged Home, FEMA, 1981.
Disclaimer
and Reproduction Information: Information in NASD does not represent
NIOSH policy. Information included in NASD appears by permission
of the author and/or copyright holder. More
NASD Review: 04/2002
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