Painting a damaged pool deck is not recommended if the substrate is crumbling, cracking, spalling, or otherwise actively deteriorating. Continuing deterioration will result in the paint also delaminating or flaking off the damaged surface. Minor damage such as chips or hairline cracks that are not actively deteriorating can often be repaired enough to paint over. A damaged pool deck with a lot of cracking and deterioration should be replaced for best results.

Staining or sealing a cedar deck or fence is highly recommended to extend its lifespan and protect it from the elements. While cedar is naturally resistant to mold and mildew, it is not impervious to damage from moisture, sun exposure, splintering, fading, and rot over time. Applying a protective finish creates a shield that preserves the wood's strength and appearance, potentially extending its life by five to 10 years.

When choosing a finish, it's helpful to understand the difference between a sealer and a stain. A sealer sits on top of the wood, whereas a combination stain and sealer soaks into the top layer. Because it penetrates the wood, a stain generally offers better protection against UV damage and rot and lasts significantly longer. For the best results that also preserve the wood's natural color, consider using a near-translucent stain.

To maintain protection, plan on reapplying the stain or sealer every two to three years, either as a DIY project or by hiring a professional.

When choosing between deck stain or paint, knowing what will last longer is important. Deck paint lasts longer than deck stain. With deck paint, you can get up to 10 years of coverage before you need to reapply. With deck stain, that time is significantly shorter at two to three years. 

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.