When taking on a deck staining project there are a few important factors to consider. One of which is weather. Rain is probably the biggest factor when staining a deck with TWP or any stain for that matter. Ideally, you will want to check the weather several days in advance before starting your project. Be sure there is not rain forecasted for the next several days. Prior to applying TWP Stain you will want to wash the wood using a quality wood cleaner followed by a wood brightener product. This will clean the surface of the wood and prepare it for the new stain.
After cleaning the wood surface it needs to dry for a couple of days. You can check the wood with a moisture meter to be sure it is ready for stain. You want it to be no more than 12 to 15% moisture before staining. If you do not have a meter typically waiting a couple of days is generally good enough. If the wood gets wet from rain at any point after washing it, it needs to dry out for an additional two days. Also, it is important that rain is not forecasted on the third day when you get ready to apply TWP deck stain. So basically you need at least three dry days before washing and staining.
Once you have ideal weather and complete the staining using TWP, it needs to dry and cure. Rain may pop up that was not forecasted and put a damper on your project. With TWP stain it is ideal to apply it in dry conditions but it can handle a little rain even after it has been applied. TWP is a deep penetrating oil based stain and because it is not film forming, a light rain can be withstood within an hour of it being applied. TWP immediately starts blocking out moisture deep within the wood fibers so you may find a light rain will simply bead up on the surface and not harm the newly applied stain. With this said obviously dry weather is best before and after TWP staining.