– Rot caused by a “wood-eating” fungus –
Summary: Dry rot is a condition of wood in which a fungus breaks down wood fibers and renders the wood weak and brittle. Excess moisture is the root cause of dry rot. Borate wood preservatives can be used to treat and prevent fungal growth in some situations.
Dry rot is caused by a fungus
Dry rot is a weakening of wood caused by one of several species of fungus. The fungus digests the parts of the wood that give the wood strength and stiffness. Weakened wood is typically somewhat dry, hence the name dry rot, and brittle and may have a blocky appearance.
Ironically, dry rot usually results from too much moisture in contact with wood. The dry rot fungus has the unusual ability to transport water from wet areas to dry areas allowing the fungus to grow in relatively dry wood. If not stopped the dry rot fungus will so weaken wood that it may eventually disintegrate.
Damage may resemble ants & termites
Dry rot is often confused with carpenter ant or termite damage. Carpenter ant damage (see What are Carpenter Ants?) is distinguished by the removal of wood and formation of clean cavities where the carpenter ants live. Subterranean termite damage is similar to dry rot in overall appearance but the presence of live termites, termite galleries and generally wetter wood will usually separate the two conditions.
Preventing dry rot damage
The most important way to prevent dry rot damage is to reduce or eliminate excess moisture. This may be as simple as repairing a leaky pipe or as complicated as stopping water infiltration through a basement foundation. A common cause of dry rot and termite damage is wood in contact with soil as occurs, for example, with a failed foundation.
If moisture cannot be controlled, or if the dry rot fungus as gained a foot-hold, then wood should be treated to inhibit the growth of the fungus (see below). Boric acid, or borate, is an excellent fungicide (a pesticide that kills fungi) against the dry rot fungus. Borate also prevents insect damage. Wood can be treated during construction, during repair, or as a remedial treatment to stop an active infestation.
Borates for structral pests like dry rot are generally applied as liquids with some type of sprayer. However, most forms of ordinary borate should not be used if liquid water is present, such as outdoors, because borates are water soluble and will wash away. In these wet situations use fused borate instead because it is made for exterior applications. Fused borate is often used to protect log ends in log homes. These cut log ends are subject to attack because moisture and rot can easily start on these exposed surfaces. Fused borate is also widely used to treat wood utility poles against dry rot.
Treating dry rot
Treating dry rot is a three step process.
- Step 1 is to get an inspection by a licensed professional at Adios Pest Control to locate and stop the source of the moisture which caused the problem in the first place. Until the source of the moisture is found nothing productive can be done.
- Step 2 is to have Adios Pest Control wood repair specialists replace any wood that is so damaged that has become structurally weakened.
- Step 3 is to have Adios Pest Control treat new and existing wood with borate to prevent future advance of the dry rot fungus and kill any fungus in the treated wood.
Call Adios Pest Control at (866) 955-7378 to get your property inspection for termites, fungus and dry rot.