Stain the deck according to the weather patterns. Weather will be your worst enemy when deciding when to stain your deck, so you will have to keep up with the weather reports and anticipate the bad weather. It is best to stain in the drier and warmer months of the year, especially in spring. If you know your area is due for a rainy or snowy season, then you should hold off until the weather is optimal.
If your deck is made from cedar, oak, redwood or other types of hardwood, then you will want to stain immediately after the deck has been built, provided the weather is good. If your deck is constructed of green pressured-treated lumber, then you must wait at least 30 and up to 90 days to allow the wood to dry.
Preparation (Other Tips)
Wash the deck thoroughly before staining and allow it to completely dry. Moisture, mildew, dirt and chemicals will ruin a staining job eventually, unless these elements are removed. If you are re-staining an older deck, wait until the stain stripper (which must be used to remove the old stain) has been allowed time to penetrate the wood, usually after an hour or two. Stain your deck on a day when you can commit all the daylight hours to the task and are not in a rush. Staining will require at least that much time and patience.
Once you are fully prepare to tackle the task, know this: the length of time required to stain the deck will of course depend on the size of the deck. But, in general, the deck will need one good, carefully laid down coat, so expect to work for an hour at the least, regardless of the deck size. Also, keep in mind that not just the floor of the deck but also the railings will have to be stained. The railings will consume the most time. Once the deck and railings have been carefully stained, the stain will need to dry for at least one hour, but preferably two or more hours.