- 1). Clean the wood. A power washer will be the most efficient way for a large house but old-fashioned scrubbing with soapy water works too. Use a detergent formulated for wood siding. Look for one that lightens and evens out the surface color in preparation for new stain.
- 2). Remove mildew unless you are using a siding detergent that already contains mildewcide. Use 1 part bleach to 3 parts water. Spray it on with a spray bottle for small areas or a garden sprayer for large areas. Let the bleach solution remain on the siding for 10 to 15 minutes, and rinse it off.
- 3). Check the siding and trim for badly cracked or rotted wood. Wood starts rotting if it gets wet and does not have a chance to dry. Check along the bottom of the house, thresholds, the soffits and windowsills.
- 4). Replace the wood and, if possible, eliminate the source of excess moisture. Trim tree branches away from the house to allow sunlight in and check gutters, downspouts and your roof for leaks if you find rotted areas up high.
- 5). Caulk around doors and windows. Use paintable silicone caulking. Choose a color close to the stain you plan to use or use clear caulking.
- 6). Allow at least two dry days prior to using stain. The wood should be perfectly dry. If you are not sure, purchase a moisture meter that is available at many paint and hardware stores. Wood should have a moisture content of 12 percent or lower before painting or staining.
- 7). Tape and mask windows and any portions of the house you are not staining if you plan to spray. Spraying stain is messy and results in a lot of over-spray. If you are applying the stain with a brush, just protect shrubbery and the ground below where you are working.