Borate Treatments
The first step before treating any log home with a borate is make sure there is no water repellent finish on the wood. Some water repellent finishes are clear and colorless, so there is no way to determine if a water repellent is present by just looking at it.

The best way to determine the presence of a water repellent is to spray the wood with water. A quart plant mister works well. If the water beads up or does not soak into the wood within a minute or so, there is something present which will inhibit the penetration of the borate.

When checking for the presence of a water repellent pay particular attention to areas under roofs, eaves, and other sections of the home protected from the sun and weather. Water repellents last much longer in these protected areas. If an intact water repellent is present, it must be removed by pressure washing or other means before treatment.

If interior logs surfaces are going to be treated, it is important to check them too, even if you are positive that they have never been coated or treated. If the home has been lived in for a year or more, interior logs will acquire a coating of cooking oil, especially around kitchen and dining areas. This oil residue must be removed with a strong detergent prior to treatment.

Why is it so important to remove any water repellent before treatment? First, the borate must be allowed to penetrate into the wood to get where insect larvae are feeding in order to do any good.

Second, if the borate does not penetrate and dries and crystallizes on the surface, it will create white deposits that may be difficult to remove. These deposits can usually be cleaned up with warm water. But if a stain or finish has been applied over them, they are almost impossible to remove without stripping. Most log home owners are particularly demanding about the appearance of their home and do not appreciate white logs. The number one cause of complaint regarding borate treatments to log homes is not efficacy but cosmetic damage.

Once log surfaces are cleaned and dry, a borate may be applied according to the manufacturer's recommendations. Some people, upon learning that borates penetrate damp wood faster than dry wood, have attempted to aid penetration by wetting the logs with water just prior to applying the borate. This will not work since once a log is dry just wetting the surface does little to raise the moisture content of the interior wood.

In addition, wetting the logs fills the surface of the wood with water, allowing less borate solution to adhere to the wood. This decreases the amount of active ingredient being applied to the logs.

After the borate treatment is completed and the logs are dry, stain or water repellent should be applied to exterior surfaces. This is where many pest control operators get themselves into trouble.

Results & Expectations
Borate treatments can be quite effective in preventing and eliminating most wood destroying organism infestations. However, the last stages of Old House Borer larvae are resistant to low levels of borate and can survive for several months after a borate treatment. Emergence of Old House Borers has been reported as long as a year and a half after treatment. Younger beetle larvae will be eliminated and eventually the infestation will end.

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