Simple Methods To Dry Osb Subfloors Ideally, subfloors ought to measure about 8 to 10% MC with the wooden flooring within 2% of that measurement. RH should be maintained year spherical between 45 to 50%. In Manitoba, things possibly somewhat dryer but if it is lower than 35% RH, http://lorenzowpibu.dgbloggers.com/1293070/an-for-depth-look-at-easy-strategies-for-sub-floor-ventilation-fans