How to Seal Wood Siding

Wood siding requires a certain amount of care to keep it looking good.

Sealing Wood Siding

Mold is a particular problem, especially in shady areas of your house. With the proper type of sealer, you can greatly reduce the chances of mold growing on your siding and protect your wood from potential water damage.

Rinse your siding with a garden hose using a spray nozzle with moderate pressure. Avoid using a high pressure washer, as it will cause water to penetrate between the boards.

Mix oxygen bleach in a bucket per the manufacturer's instructions. You can purchase oxygen bleach at most hardware stores. The higher-priced products with a greater quantity of oxygen work best.

Use a long-handled scrub brush to scrub all of the siding with the oxygen bleach. Leave it on for 15 minutes, and then hose it off with a garden hose. Allow the siding to dry thoroughly.

Apply a good quality water repellent wood sealer to the siding with a paint roller. Read the label to make certain that the sealer is resin-based and not oil- or vegetable-based, as they encourage mold growth. The sealer can contain a stain, or it may be clear. Allow the sealer to dry. If the manufacturer recommends a second coat, apply it once the first coat has dried thoroughly.

Things You Will Need

  • Oxygen bleach cleaner
  • Long handled scrubbing brush
  • Bucket
  • Garden hose
  • Resin-based water repellent sealer
  • Paint roller
  • Paint tray


  • Do not use a bleach-based cleaner to clean your siding. Not only will it cause the siding to fade, the bleach will kill flowers and trees around your home. Read labels carefully; the chemical name for bleach is sodium hypochlorite.

About the Author

Larry Parr has been a full-time professional freelance writer for more than 30 years. For 25 years he wrote cartoons for television, everything from "Smurfs" to "Spider-Man." Today Parr train dogs and write articles on a variety of topics for websites worldwide.