1) Title and Dates: Brown rot decay of untreated wood steps (July 24, 2004)

2) Deterioration Agent: Gloeophyllum sepiarium - A brown rot fungus

3) Geographic Location: Old Town, Maine, USA

4) Description of Problem: Untreated wood, I think s. yellow pine, was used for steps leading up

to this deck. The steps were built in 1999 along with the house, and the decay problem was

very advanced by 2004. This was likely an issue within a couple of years of being built, although

nobody has fallen through, yet. 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 G. sepiarium. 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 two-fold: 1) the steps will need replacing, pronto, 2) the renters

are at risk for falling through. Brown rot fungi will reduce strength in the wood quickly.

The first picture is of this step. The second picture is a close-up of G. sepiarium.

5) Remediation Strategy: These steps should be replaced, along with the stringers. Following a do-

it-yourself approach is fine, but the wood needs to be treated. This is especially true of the stringers,

and if you cut them, the exposed untreated wood should be painted or Cu-napthenate brushed on.

If treated wood is used for the step, be sure if cut to brush treatment on newly exposed wood faces.

If the owner wishes to repaint, the paint needs complete coverage and yearly inspection. I would

personally use wood treated for ground contact (0.4 or 0.6 pcf) for stringers, and make sure they are

resting on something other than soil, if possible.

6) Avoidance Plan: Other than using treated wood or applying an effective layer of paint (perhaps with

some treads to avoid wear) I would try to keep the grass mowed next to the steps, and I would remove

the debris, especially woody debris, from under the deck. This material is in ground contact in the dark

and will vector new fungi into the structure. Also, inspect the rest of the building annually for brown rot.

7) Comments: