Staining a redwood deck is necessary if you want the wood to retain its beautiful hue. If redwood is allowed to weather without being stained, it will turn into an iron-grey color. Without staining, the wood could also crack.
With proper care, a redwood deck will last for many years.
Clean the Deck
You first need to remove old stains, dirt, and mildew from the redwood deck.
To spot treat decks, use a deck cleaning solution, but do not dilute it. You can use a mild dish-washing detergent, on the spots especially if they are oily.
Wet the deck before cleaning to soften the wood cells.
Use a bucket of water mixed with the appropriate amount of deck cleaner. You can also use mild dish soap instead of, or in addition to, the cleaner.
Pour a small amount on a limited area of the deck, then brush with a stiff broom or brush. Redwood is a durable and resilient wood, so it stands up well to being brushed. This cleaning will remove a small top layer of wood. Rinse the washed area thoroughly, then move on to the next part of the deck.
Once you have completed cleaning the entire deck, allow it to dry completely. This will take several days. Avoiding walking on the deck until it's completely dry.
Choose the Stain
For a redwood deck, a semi-transparent stain is an ideal sealant. You can find a color that closely resembles the natural color of the wood, or you can match the stain color to the trim or color of the house.
Semi-transparent stains soak into the wood, giving your redwood deck protection from rain and wear for two years or more. It also won't peel or flake as a solid stain will.
Solid stains do not hold up well to foot traffic either, and will soon wear down across footpaths leaving an unattractive space that has no stain.
Once you’ve applied a solid color stain, you cannot go back to a semi-transparent, you need to reapply solid stain each time.
For all of these reasons, semi-transparent is the best type of stain to use for decks.
Apply the Stain
To speed-up the staining process, you can use a paint sprayer, a garden sprayer, or a roller. However, none of these methods is as effective as a large brush for getting the stain inside of the wood and sealing the wood off.
A combination of the two application methods works well. Spray or roll a generous amount of stain onto a six-foot square area of your redwood deck, then go back over the area with a good stain brush and more stain to work the mixture into the wood.
This method will give you a long-lasting finish but goes more quickly than hand brushing alone.