Michigan State University Extension
Home Maintenance And Repair - 01500040
06/24/03
Causes of Mildew In Carpets
Mildew gets its food from the root system which
works its way into the material on which it is growing.
Mildew can only get its food from natural materials such
as protein, cellulosic, etc. In a carpet the protein
material would be wool, the cellulosic would be jute or
cotton.
If a carpet is used where mildew growing conditions
are present then all man-made fibers (both face and back)
should be used. The possibility of mildew growing on this
type of carpet is very small and, even if it does, it
will not damage the carpet.
The damage mildew can produce is twofold. The root
system can remove as much as 90% of a natural fiber's
strength in two weeks. After the mildew growth has taken
place and the fibers dried out, a crackling sound can be
produced if the rug is rolled. The crackling sound is the
result of the crush of the hollowed backing fibers. If
the mildew growth was in the backing fibers, the rug may
have little strength and can easily be pulled into or may
even fall apart if an attempt is made to move the rug. If
damage this severe has taken place, then nothing can be
done to correct it other than cutting out the damaged
area.
Mildew can also leave a discoloration inside the
fibers which is almost impossible to remove. The color
will vary depending upon the type of mildew from white to
black, reds, browns and greens.
If it is neither possible nor practical to prevent
mildew growth, the carpet may have to replaced with one
made from all man-made fibers.
The construction of many homes with the family or
recreation room below ground produces ideal conditions
for mildew growth. An unsealed concrete slab will allow
moisture to pass from the ground into the room. If a
carpet is to be installed, three steps should be taken.
First, seal the concrete. Sealers can be obtained from
hardware and paint stores and can be applied with a
paint brush. Install only a carpet or rug with all man-
made fibers, both face and back. If moisture and mildew
are still a problem, use a dehumidifier.
This article was written by Anne Field, Extension
Specialist, Emeritus, with reference from The Carpet and
Rug Institute - Mildew.
This information is for educational purposes only. References
to commercial products or trade names does not imply
endorsement by MSU Extension or bias against those not
mentioned. This information becomes public property upon
publication and may be printed verbatim with credit to MSU
Extension. Reprinting cannot be used to endorse or advertise
a commercial product or company.
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Issued in furtherance of MSU Extension work, acts of May 8 and June 30, 1914, in
cooperation with the U.S. Department of Agriculture. Thomas G. Coon, Director,
MSU Extension, East Lansing,MI 48824. This information is for educational
purposes only. Reference to commercial products or trade names does not imply
endorsement by MSU Extension or bias against those not mentioned.
This file was generated from data base 02 on 02/04/08.
Data base 02 was last revised on 06/24/03.
For more information about this data base or its contents please contact
strausc@msu.edu .