Although timber is a porous, absorbent substrate, it will not “soak” water up like a sponge and therefore although the surface may be wet, the main body of the timber is likely to be dry. While it is difficult to be precise, two good drying days should be adequate. If rainfall has been for a longer period, as much as one week or more of dry weather may be necessary for the moisture content of the timber to reach an acceptable level.