How to waterproof already painted wood
Painted wood surfaces, such as siding, decks or patio furniture, need a barrier from moisture. The optimal method is by adding a layer of moisture-resistant primer to the wood before applying a finishing layer of paint.
The experts at Home Improvement Super Pages state that "the problem is that wood is a notoriously thirsty substance, and it is easy for water to get absorbed into the grain itself." For wood that's already painted, adding a layer of wood sealant is the easiest method for waterproofing. Larger projects can take a couple of days to complete, but the added protection is necessary to combat moisture damage.
- Painted wood surfaces, such as siding, decks or patio furniture, need a barrier from moisture.
- The optimal method is by adding a layer of moisture-resistant primer to the wood before applying a finishing layer of paint.
Mix 60 ml (1/4) cup of liquid detergent with 4.5 L (1 gallon) of water in a bucket. Scrub the painted wood surface with a cleaning brush dipped in the soapy water.
Rinse with clear water using a garden hose. Allow the surface to dry for two to three hours.
Apply an even layer of silicone-based or polyurethane wood sealant using a paint sprayer. These products are available at all home improvement centres. Give the sealant product 24 hours to completely dry.
- For complete moisture protection, it's best to strip the paint, and add a primer coat. Clear coat sealants won't last as long without a layer of primer coat beneath.
- Wear safety glasses when using chemicals, such as sealants.
- Work in a well-ventilated area to minimise the fumes.