Abstract:
Molds are an increasingly important issue for all building materials, including
wood. While washing with bleach is a commonly recommended method for removing
molds, and the associated discolorations, there is surprisingly little information on the
effectiveness of this treatment. The ability of mold removal treatments to brighten
wood and eliminate fungi was assessed on Douglas-fir (Pseudotsuga menziesii) sapwood
lumber heavily colonized with mold and sapstain fungi. The boards were subjected
to different washing treatments: wiping with bleach solution, wiping with water,
and a no-wash control. Samples were evaluated visually for changes in mold appearance
and then fungi were isolated from the surface of the wood. Replicates from the various wash
treatments were further treated with three biocide formulations. The effect of
the mold control treatments on visual appearance and fungal diversity was assessed 1
month after treatment. Increasing bleach concentrations from 2.5 up to 20 percent solution
had no effect on the appearance of the wood following the wash treatment, nor did
such treatments completely eliminate fungi from the wood surface. The chemical mold
prevention treatments tested were not effective in sterilizing the wood, nor did they improve
the visual appearance.
