I have a 2-story barn built with Hickory & oak from trees on our property. No doubt there were powder post beetles in the trees and over the last 7 or 8 years I am seeing signs of their fine dust on the floors. Their holes are very tiny and probably would take many, many years for them to do any structural damage in rough-cut 2x6s, 2x8s,2x10s,2x12s, etc. About 2 years ago I sprayed the ceiling joists with Bora Care but recently we’re again seeing dust on the concrete floor. Did I not spray
It must be applied to bare wood that has no sealer or stain on it. Try applying the original Shell Guard borate that you mix. It takes 2 to 3 weeks to dry but will give you the most penetration into the wood fiber for best control. All exposed wood on the building should be treated. Call Timeless Wood Care Products at 800-564-2987 to order the borate.