How to Waterproof Siding

By Home & Garden Last updated Friday, May/31/2024

Preparing the Siding before Sealing

1). Mix a solution of wood cleaner. Wood cleaner is typically sold in a concentrated form. Follow the manufacturer's instructions regarding the dilution.
2). Wet the siding down with a hose and apply the mixed wood cleaner. Allow the wood cleaner to sit for 15 to 30 minutes.
3). Scrub the siding down with a nylon scrub brush. Then rinse the siding down thoroughly with water.
4). If you are planning to stain the wood, and if the wood has darkened during the cleaning process, apply wood cleaner to the siding. Some types of wood contain high levels of tannins. This natural preservative can bleed to the surface of the wood and cause discoloration and darkening. Oxalic acid in wood brightener will neutralize tannins and restore the natural color and luster of the siding.

Leave the wood brightener on the wood for 45 minutes, then rinse thoroughly with water.
5). Allow the wood to dry for at least 24 hours before applying a paint or a stain to the wood.

1). Use a paint brush, roller or sprayer to apply a single coat of exterior wood primer. The primer is designed to bond well with the wood and provide a solid surface for the paint. Follow the manufacturer's instructions regarding drying time before applying paint over the primed wood siding.
2). Use a paint brush, roller or sprayer to apply a coat of paint over the primed wood surface. Start on one corner of the siding and work your way along the direction of the siding boards. Follow the manufacturer's instructions regarding drying time before applying the second coat of paint.
3). Apply a second coat of paint over the siding.

1). Use a paint brush, roller or sprayer to apply a single coat of wood stain to dry, bare wood. Start in one corner and work in the direction of the wood. Maintain a wet edge as you work and stain a single board or two boards at a time.
2). Feed the wood as much stain as it will absorb, but be careful not to overapply the stain.
3). After the wood siding is stained, wait 15 minutes. Then go back over the wood with a dry brush to remove any excess stain that has not completely penetrated the wood's surface.