Applying an exterior wood stain to pressure treated wood has a number of myths surrounding it, including the old canard that a wood which has been pressure treated should be left to face the elements untreated for several months. This supposedly gives the wood a look of authenticity, and a tougher exterior, but the fact is that leaving your pressure-treated wood for several months can cause it damage, and may even expose it to the risks of mold and dry rot that exterior wood stains are designed to prevent.
How Long Should Pressure Treated Wood Be Left?
Before applying an exterior wood stain to any wooden furniture, decking or window frames that have been newly pressure treated, you should leave the lumber for around 30 days. A month is long enough to provide good weathering, and you are less likely to be risking dry rot or mildew if you expose the wood for this amount of time. There are also some exterior wood stains which an be applied directly to the pressure treated lumber, whether it has been weathered or not. Check whether your sealants and stains can be used in this way by reading the label. You can also treat certain kinds of woods, such as cedar and redwood, without having to wait.