Mold on carpet

Jessica Fletcher <jfletcher [at] denverartmuseum__org> writes

>We recently experienced minor flooding under the floor carpets in
>the elevator lobby of one of our galleries.  As a result, mildew is
>starting to grow.

There have already been several good suggestions about minimizing
mold growth, including installing powerful fans, raising the
temperature of the library, lowering the humidity, and removing the
carpet. Keep in mind that once mold has begun to grow in the carpet,
the microscopic hyphae remain in place even after the water supply
has been eliminated. All these hyphae provide an excellent food
supply for book lice, so expect that an infestation of booklice in
your carpet will follow, sooner or later . You can take precautions.
Without them, as soon as you have your floor dry, and the relative
humidity of the library stable at 40% (to make life difficult for
lice), map out your library, place your insect traps, and begin
monitoring.

The institution where I used to work had the flood, followed by the
mold, followed by the lice, and we controlled and, I think, stopped
the lice with a kind of laundry detergent. In general, we didn't
want to use anything seriously toxic around staff, and in
particular, didn't want poisons because staff members were pregnant
at the time. We purchased one box of "Borax" laundry detergent ( $3?
$4?), and sprinkled it all around where the lice had been discovered
in traps. It was left in place for a weekend, then vacuumed away. At
least in the sense that anything can be vacuumed out of a carpet.
Anyone who has lived with wall to wall carpets knows that dirt,
dandruff, mold, and dead insects all fall into carpets and stay
there forever, regardless of how well they are cleaned. The residue
of Borax, combined with holding RH in the library at 40%, acted to
drop catch numbers of trapped insects by about 95% in three months,
and to about zero in six months. Catch numbers remained very low
thereafter, at the level of random intrusions of insects, for
example, one or none per trap in three months. The levels indicating
entrenched, well-nourished, breeding populations can easily be 30
insects of all stages of growth, on one trap, in a couple of days.

On a related note, library staff continue to produce healthy,
charming, intelligent, and good-looking children.

So, be on guard for the next developments within your library carpet
ecosystem.

James Hay
Senior Conservator, Furniture and Decorative Arts
Canadian Conservation Institute
613-998-3721


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                  Conservation DistList Instance 14:42
                 Distributed: Monday, February 5, 2001
                       Message Id: cdl-14-42-003
                                  ***