DIY Waterproofing for Wood

Check the wood you will be waterproofing for any damage. It will not help to seal a piece of wood that is already rotting or plagued with pests. If you find any damage, replace the area before you begin waterproofing.

Clean the wood. Use a wood soap such as Murphy's Oil Soap. Dissolve some soap in a bucket of warm water and throughly scrub down the wood. Use the abrasive side of a sponge if the wood is not too dirty, or steel wool if it is really grimy. Sand stubborn areas with fine-grit sandpaper to remove all of the dirt. In order to seal the wood it needs to be free of all dirt, grease, oil and mildew. Once you have thoroughly cleaned the wood, wash it down with clean water to remove any excess soap.

Wipe off any excess water with dry rags so that the water does not seep into the wood. Wait for the wood to dry completely before sealing.

Choose a sealer. Many different types of waterproofing sealers are available at hardware stores. Some are clear and come in matte to glossy finishes, some will add a stained effect and some come in various colors. You can also choose between oil- and water-based coating, or a hybrid of the two.

Use a large bristle brush or a roller to paint the sealer onto the wood. Make sure to cover the entire piece of wood and not to miss any spots. If you spill any sealer or make any mistakes, you can remove the excess sealer with mineral spirits while it is still wet. Keep the wood away from any moisture until the sealer is completely dry.