Yes, it is generally a very good idea to seal your deck after pressure washing. Power washing removes not only dirt and debris but also a thin layer of wood, leaving the surface exposed and more susceptible to weathering. Sealing is almost always needed after this process. After a general cleaning, sealing isn't automatically necessary if the existing sealant is still intact. You can test the surface by placing a few drops of water on it. If the water beads up, the sealant is working. If it soaks into the wood, it's time to apply a new sealant. If it has been a few years, it's wise to remove the old sealant, wash the deck, and reseal for maximum protection.

Choosing the right product involves understanding deck material, desired finish, and local weather conditions. Opt for high-quality, weatherproof formulations ensuring long-term durability and appearance retention.

Staining a deck with a rag is typically a better option than using a brush, as it helps the stain penetrate deeper into the wood. However, both brushes and rags are best reserved for detailed work because using these tools on an entire deck can require tediously crawling around on your hands and knees. A pad applicator, sprayer, or roller are preferred alternatives to applying stain over the majority of a deck. Use a rag for railings and other detailed work, and let the wood soak up as much of the stain as possible before wiping away drips or pools.

It’s best to prime composite decking before painting. This promotes better paint adhesion, helps create a smooth finish, and can mean the paint job will last longer. Always follow the manufacturer’s instructions for application, allow ample primer drying time before painting (typically 24 to 48 hours), and thoroughly clean the deck boards to promote the best adhesion.