Biodeterioration Diagnostics Database

While inspecting a very old garage that is beginning to lean to one side, a likely brown rot fungal infestation was observed. The garage is constructed of wood over a cement floor, however the wooden walls of the garage are in direct contact with soil. The garage was present when the associated house was purchased in 1979. It is unknown whether the wood used to build the garage has been treated, and if it has, what the chemical or dosage was for the treatment. Also pertinent, the garage is located underneath a pine tree. Pine needles have fallen on the roof and collected in piles on the roof that have been the site of their decay from needles into unidentifiable organic matter. These piles could be a source of moisture or fungal spores. The other potential source of fungal colonization could be the soil. The infestation was observed boards in the wall of the garage near the ground; it was also observed in wood trim along the edge of the roof. The full extent of fungal networks and growth is unknown, however there are several areas of concentrated symptoms, such as brown flaky wood with visible cubicle checking.

Untreated wood, most likely southern yellow pine, was used for steps leading up to the deck shown in the attached images. The steps were built in 1999 along with the house, and the decay problem was very advanced by 2004. The steps look like they were painted gray, but the paint has chipped and worn, exposing untreated wood. The deck itself was 0.25 pcf treated wood and, at the time of these photos, did not show signs of the fungus (sporophores, cubical checking, etc.). Clearly, the agent of decay is a fungus. The sporophore belongs to Gloeophyllum sepiarium, also known as the 'mazegill' fungus. You can see its sporophore as a rust-colored protrusion (a small shelf fungus) at the front end of the step. It is a brown rot, so the problem the landlord faces here is three-fold: 1) the steps need replacing, immediately, 2) the renters are at risk for falling through the deck because brown rot fungi reduce strength in wood quickly and 3) the mycelial mass of the fungus in this wood can act as a source for problems elsewhere, including the deck. Assuming CCA was the treatment for the deck boards (pre-2004), there should have been little leaching since being built and there is lower potential, but at 0.25 pcf, you could still have decay. Some brown rot fungi are more tolerant/resistant of heavy metals. Also, one of the images shows that the nail fasteners have failed, and they do not look galvanized, etc. There was likely galvanic corrosion and possibly iron leaching into the wood which, for iron-dependent brown rot fungi, may be a problem.