Deck stain is meant to enhance a deck, as well as protect it from harsh weather conditions. If you recently bought a house with a deck that has a dark stain, or you applied a dark stain to your deck in the past and want to change the shade to something lighter, it isn't an impossible task. It is, however, a strenuous one. If you are lucky, the new lighter stain will go on over the darker one with no trouble, but in most cases, you are going to have to remove the old stain and reapply.
Test the lighter stain in a location where no one will notice. Apply the stain with a rag and let it sit for several days. Wait to see if the dark stain is going to bleed through to the top. If it doesn't, then you can proceed with the application process. But if it does show through, you will either have to find another stain or follow a few extra steps.
Clean the deck with a pressure washer to remove debris and allow the deck to dry overnight.
Sand any peeling stain areas with coarse sandpaper to remove the peeling stain.
Apply a stain stripper to the deck to remove the old stain. Brush it on with a polyester brush and let sit for 15 minutes. The old stain will bubble up as the stain stripper works on the finish. Work in small sections.
Scrub the bubbled-up finish with a bristled brush to remove the stain. Scrub with the grain of the wood. Once you're finished, rinse the deck with water to remove the stripper. This process could take a few days if you are doing it alone.
Apply a wood brightener to the deck once it is all stripped. This will deactivate the stripper and brighten the wood. Apply the brightener at each section right after rinsing it off.
Combine the cans of stain you have chosen in one bucket and stir up the stain with a paint stick. This will ensure that all the stain is the same colour. It is better than working out of many smaller cans that might have shade variations.
Apply stain with a bristled paintbrush. Brush with the grain and coat the deck evenly. Allow the finish to dry for at least a day before you use the deck.