The potential for fungal (Penicillium and Aspergillus spp.) growth on
four different types of ceiling tiles was evaluated in static chambers
. It was found that even new ceiling tiles could support fungal growth
when at equilibrium with a relative humidity (RH) as low as 85% and c
orresponding moisture content (MC) greater than 2.2%. Used ceiling til
es appeared to be more susceptible to fungal growth than new ones. In
the 70% RH chamber with wetted tiles under slow-drying, non-equilibriu
m conditions, fungi could still proliferate as long as the moisture le
vel in the ceiling tiles was adequate. Fungal growth could be limited
if the wetted ceiling tiles were dried quickly and thoroughly.