I recently had the Terminix Co. inspect the crawl space under my house. They reported no termites, however they reported that there is a serious problem developing with a fungus that attacks wood floor joists and will cause them to rot, they recommend a treatment called "Borate" and claim it will solve the problem and has a lifetime guarantee and will cost about $1000 for 1,800 sq.ft. They installed moisture barrier & vents approximately 6 years ago. The house is about 84 yrs old and in very good shape. Please let me know if there is anything on the market that is less expensive/or better. What do you recommend?