Borax and boric acid mixtures have well documented positive effects in the treatment and prevention of wood floor rot and infestation. Many commercially available products offer borax treatments for specific purposes like wood treatment and rot repair, but homemade solutions are simple and inexpensive to make.
Borax is a desiccant that dries out water-damaged wood and helps seal and protect it from future rot. It is also a natural pesticide that kills termites, fungus and other wood floor enemies.
You can make borax wood floor treatments at home by preparing a mixture of boric acid and warm water or boric acid and glycol. While glycol is more toxic, it is also more effective at treating existing problems.
Prepare your floor for borax treatment by cleaning out any rotted areas, removing any debris and heating the floor prior to application to facilitate better penetration of the wood and increased absorption.
Borax is water soluble, so it is not a permanent solution for wood that is often exposed to water. Tim-Bor is a commercial borate product that protects against rot for over 30 years.
Sodium borate, or borax, is considered environmentally safe, especially when compared to other wood floor treatments. It does have oral and dermal toxicity, according to the US Environmental Protection Agency, so apply with caution.