Decay fungi can cause severe structural damage to any wood member, even wood species such as redwood and cedar. All that is needed is a source of water in contact with the wood. Decay will occur in untreated wood in direct contact with ground, cement or concrete, or exposed to a source of moisture such as rain seepage, plumbing leaks or condensation. Wood kept dry will never decay!
Brown rot fungi feed on the wood's cellulose, a component of the wood's cell wall, leaving a brown residue of lignin, the substance which holds the cells together. Infested wood may be greatly weakened, even before decay can be seen. Advanced infestations of brown rot are evidenced by wood more brown in color than normal, tending to crack across the grain. When dried, wood previously infested will turn to powder when crushed. Often, old infestations of brown rot which have dried out are labeled as "dry rot." This is really a deceiving term since wood will not decay when dry.
When white rot attacks wood, it breaks down both the lignin and cellulose causing the wood to lose its color and appear whiter than normal. Wood affected by white rot normally does not crack across the grain and will only shrink and collapse when severely degraded. Infested wood will gradually lose its strength and become spongy to the touch.
Most decay fungi are unable to conduct water very far and can only attack moist wood. However, Poria incrassata, called dry rot or the water-conducting fungus, will decay wood which would not be attacked by typical decay fungi. Poria infested wood is often mistakenly identified as subterranean termite damage. This type of fungus can transport water for several feet through large root-like structures called rhizomorphs. Once established, it can quickly spread through a building and destroy large areas of flooring and walls in as little as a year or two.
Typically, infestations of Poria begin in dirt filled porches, damp crawl spaces and basements where wood is in contact with the soil. They also begin in moist concrete or damp bricks. At first, yellowish mycelial fans grow over the surface of joists and sub-floors, or in protected areas. Irregular root-like rhizomorphs may appear on foundations, framing, sub flooring and other moist areas. the rhizomorphs are dirty white when young but turn brown to black with age. They are typically 1/4 to 1/2 inch wide, but can be an inch or more in diameter in old infestations. they are often hidden in concrete, masonry or behind wood structures. Fruiting bodies do not always form, but when they do they are found on well rotted wood and are flat, up to 1/2 inch thick, and pale olive-gray with a dirty white/yellow rim when young. With age they become dry and turn brown to black. The under surface is covered with small pores.
When Poria infested wood dries it usually shrinks and cracks across the such cracks or depressed areas in painted woodwork may be the first evidence of a Poria infestation. The best tool for discovering a Poria infestation is a moisture meter. If wood has a moisture content above 40% and there is no apparent source of water, you are probably confronting Poria incrassata or an infestation of subterranean termites. In either case the wood should be treated as soon as possible.
Molds and stain fungi are sometimes mistaken for decay, and while they may discolor wood, they cause no structural wood damage. The presence of molds and stains, however, is a sign that conditions are favorable for decay fungi and a preventative treatment may be necessary. In addition, molds can increase the capacity of wood to absorb moisture, opening the door to attack by decay fungi.
Boracare application methods for treating beetle and decay infestations are similar. Treat the infested and surrounding area with Boracare according to label directions. When practical, infect diluted Boracare solution into beetle emergence holes and galleries. It is important to treat the entire infested wooden member. If only a small portion of a wood member is treated there is a possibility that the amount of active ingredient in the treated area may eventually diffuse to a level below that needed for effective control.
Since wood can contain active beetle larvae or fungal spores with no surface evidence of infestation, the best method of control is to treat the entire area where an infestation has been found. This would include all of the wood in a crawl space, wall or attic showing any sings of damage.
Infested wood flooring can be treated with Bora-Care by spray or brush application. It will be necessary to remove any existing finish by sanding or stripping prior to application. Refer to the Boracare label section on treating flooring for application rates and methods.
When controlling decay fungi, treatment with Boracare should not be considered as a replacement for moisture control. Leaky plumbing and drain spouts should always be repaired in addition to treatment. Wet crawl spaces should be vented and plastic sheeting installed. Structural wood members that are no longer sound must be replaced. Although Bora-Care will kill beetle larvae and decay fungi, it will not add strength to damaged wood.
Uninfested wood may be protected from insects and decay with a Boracare treatment. After treatment, exterior treated wood surfaces should be coated with a water repellent finish such as paint or stain. It is important to allow the Boracare to completely dry before applying any protective topcoat.
Treating Wood In Contact With the Ground For Decay
Bora-Care may be applied to wood in contact with the ground or soil. However, water passing through the wood will limit the life of a BoraCare treatment. A better approach is to inject Jecta Diffusible Boracide ( Jecta Gel ) into the high risk area. Jecta will last longer than Boracare in this situation. In addition to eliminating and protecting the wood from decay, Jecta is also effective against subterranean termites. However, Jecta should not be used for treating wood boring beetle infestations. Refer to the Jecta Diffusible Boracide specimen label for complete application instructions.
The time required to completely eliminate a beetle infestation with Boracare is influenced by several factors. These include the time of year treatment is performed, beetle species, the degree and age of the infestation, the wood species, moisture content, wood thickness and application technique. Boracare is extremely toxic to beetle eggs and young larvae. However, older larvae of species such as old house borers are more resistant and must ingest a large quantity of the treated wood in order to be killed. Since some of these older larvae can take several years to mature and eat very little wood, they may be able to pupate an emerge several months after treatment. This normally occurs only in logs or large beams. Any beetles which do emerge cannot re-infest treated wood and their life cycle is broken at that point. Should isolated beetle activity continue after treatment, individual larvae may be located and eliminated using localized infection techniques.
The season when treatment is performed may also influence the time required for total eradication. Applications during late fall an winter (the beetles dormant phase) have limited immediate effect on mortality. When the larvae become active again in the spring, they will ingest the treated wood, causing death. In general, complete elimination of large beetles such as old house borers may require several months to a year. However, the large majority of active beetle larvae and eggs will be killed more quickly.
Elimination of surface molds and decay fungi progresses rapidly after treatment with Boracare. Within one week, molds will begin to disappear and fungi fruiting bodies will begin to dry out. Although Boracare has no odor, the decomposition of dead fungi may occasionally result in a "rotten" smell a few days after treatment. This odor will only last a few days and can be eliminated with the use of biological odor control agents.
Mixing: 1 part Boracare to 1 part water.
Each finished gallon of solution will treat up to 500 Square Feet
Boracare can be purchased in 2 different sizes: