To waterproof wood, clean and dry the surface, and apply multiple coats of a waterproofing agent. These agents can be oils, varnishes, primers, stains or sealers and are available at most hardware stores. It can take hours or days to complete this project, depending on the type of agent used.Continue Reading
Scrub the surface of the wood with warm, soapy water. Make sure to remove any dirt, mold and oils. Sand the wood, if necessary, to remove any remnants of sealers, varnishes or paints used previously.
Place the wood in a warm, well-ventilated area to dry. Make sure that the wood is completely dry before applying the agent.
Coat the surface of the wood with your choice of waterproofing agent. If using varnishes, sealers, stains, primers or paints, use a paintbrush or paint roller to apply the product. For oil-based agents, use a cloth or rag to apply the coats.
Ensure that the wood is kept dry and within the temperature range specified by the waterproofing product for the required amount of time.
Apply one or more additional coats of the waterproofing agent if specified on the product's instruction label. Oil-based agents actually penetrate into the wood grain and require several applications to be effective and lasting.