WOOD DESTROYING FUNGUS
Wood destroying fungi are plants. One of the things that make these plants different from the petunias in your flowerbed is that wood destroying fungi don't have leaves with chlorophyll in them, so they can't manufacture their own food. Instead, these plants are parasites. They attach themselves onto (or into) existing wood and then use their "roots" to extract the stored food material in the wood. This stored food is in the form of cellulose.
Wet wood is no good!
Wood destroying fungi need four things to survive:
- A food source (wood)
- Adequate temperatures (usually +50ºF)
- Oxygen (they don't use carbon dioxide like green plants)
- Moisture (moisture in wood at 20% or more)
Moisture is the one factor over which we can have some control. Sources of moisture could include a leak, drainage problem, improper sprinkler adjustments, or poor ventilation (condensation), etc.
BROWN ROT - DRYROT - WET ROT
(Cubicle brown rot)
There are many species of wood destroying fungi. When we are dealing with structures, though, there are three principle types. The one we encounter most frequently is known as "dryrot". This fungus is also known as "brown rot" or "wet rot". The last two names are much more accurate than the common name of dryrot. That's because wood won't rot if it's dry!
Brown rot is a plant you won't actually see. What you will see is the results of the infection.
The damaged wood will have a reddish-brown color and will appear "weather-checked". This breakage of the wood into cubes and discoloration is where the fungus gets its name.
Brown rot damage is very easy to distinguish from the damage done by wood destroying insects. However, we do find this infection in wood that has also been attacked by wood destroying insects. When this happens it usually requires an expert to make an accurate identification.
In the picture at the right try to find the subterranean termite evidence.
(Hint: It's under the brown rot damage.)
We also find brown rot in wood siding or trim that has been kept wet by continual contact with soil or by irrigation sprinklers striking the building. It is common to find brown rot damage in the bases of patio or porch cover support posts and garage door frames.
White rot, or white fungus, is another fungus commonly found in structures. The fruiting body of this fungus appears as a white, cottony mass on the surface of the infected wood member. (See the picture at the right.) The white part you see is the fruiting portion of the fungus, where its spores (like seeds) are produced.
The damage takes place in the wood below the surface where the "roots" have penetrated the wood and digested it. The picture above shows a thin line of whiterot. Look for it where the fungus is sandwiched between the two infected floor joists.
We also find this fungus in attic areas at roof leaks, under exposed wood decks, and in any other area where the wood remains moist for long periods of time.
The first thing that must be done to control wood destroying fungi is to control the moisture source (if practical). Once the moisture problem has been corrected, the damaged wood members usually need to be removed and replaced with new material. It is not uncommon for fungus damage to extend beyond the area where we first see it. The damage can easily extend into concealed areas beyond the area visible at the time of the inspection.
WATER CONDUCTING FUNGUS
(Poria incresata, etc.)
These fungi represent the "horror stories" of fungus damage. They are capable of drawing the necessary moisture through a long, root-like structure, while the damaging portion of the fungus attacks dry, sound wood elsewhere in the structure. In some cases the moisture source may be dozens of feet away from the affected structure.
That's the bad news.
The good news is that these fungi haven't become a problem in our area yet. Those of us in the trade have been watching this issue closely. When it starts to become an issue we'll do our best to get the word out. I will try to keep this website up to date on this matter, so check back occasionally if this matter is of concern to you.
OTHER TYPES OF FUNGI
(Non-wood destroying fungi)
Mold has become an increasingly visible issue recently. Molds and mildews are types of fungi that are alleged to be associated with respiratory and other health issues. These fungi could be present in a structure and we would have no way of knowing about it. We have had no training in this area and we don't know how to detect or control these types of fungi. Our training and our license qualify us to render opinions only about wood destroying fungi (and other wood destroying organisms). If you are concerned about mold or mildew you should contact a licensed air quality specialist, industrial hygienist or other licensed individual with expertise in this area.
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