Biodeterioration Diagnostics Database

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.