Stripping stain from a deck is an important first step to making your deck look like new again. Over time the old stain becomes weathered due to exposure to sunlight, rain, heat and cold. Weathered stain will get darker, and often forms spots where the stain has worn off completely. Never paint new deck stain on top of the old stain, because the colour will come out blotchy and uneven.
Remove everything from the deck. Use your garden hose to wet the grass and surrounding plants. Place plastic dust sheets around the perimeter of the deck to protect the grass. Use more dust sheets to cover any nearby plants.
Put on your protective gear. Strippers are very strong and can cause severe skin irritation and eye damage. Fill the pump-up sprayer with the stain remover and cleaner. Saturate the entire deck with the stain stripper. Allow the stripper to sit for 15 minutes.
Use your long handled scrubbing brush to scrub the deck when the stain begins to lift. After scrubbing the deck, use a pressure washer to rinse off the stain. Turn the tip of the pressure washer's wand so that the water comes out in a wide spray instead of a straight line. If you do not adjust the washer you will create deep gouges in the wood.
Hold the tip of the power washer at least 30 cm (12 inches) from the deck. Walk the lengths of the planks while you are washing. Spray at least two deck boards at a time. When you move to the next set, overlap the previous board with the power washer. This will help reach the edges of each plank.
Rinse the plastic dust sheets and remove them. Spray down the grass and the surrounding plants. This will neutralise the chemicals in the stripper and keep it from killing the grass and plants. Allow the deck to dry and do a water test on several areas.
Sprinkle some water on the deck. If the water soaks in, the deck is free from stain and sealers. You will have to reapply some stripper if the water beads up. Allow the deck to dry overnight before staining.
Use the appropriate stripper for the best results. Not all stains are alike. Some stains are water-based and some are oil-based.