HOW WET DOES BORATE-TREATED WOOD NEED TO BE BEFORE BORATE WILL LEACH OUT?
Borate will leach out only while wood is exposed to flowing liquid water and the moisture content is above fibre saturation (averages around 27% moisture content, although this number varies depending on wood species). This can occur when the wood has extended contact with rainwater or very heavy condensation. Moist air, even at 100% relative humidity, does not cause loss of borate.
