The life expectancy of deck boards varies widely based on the material, climate, and maintenance. Untreated wood boards typically last 10 to 30 years with proper care, while pressure-treated boards can last up to 50 years. Hardwoods generally outlast softwoods. Composite boards also tend to last longer than natural wood. Environmental factors like arid or humid climates can shorten a deck's lifespan. To extend the life of wood decking, it's important to consistently clean and seal it to protect against moisture, UV light, and insects.

Unless you’re using a 2-in-1 formula or painting over an existing coat of paint, it pays to apply a coat of primer ahead of your new paint. Decks see a lot of footfall and exposure to extreme and sudden temperature changes and moisture levels. The primer promotes better paint adhesion, moisture repellency, and a smoother finish, which means you’ll often need fewer coats of paint. 

There are approximately 5.33 board feet in a 2x4. You can use the board foot calculator in this article to easily find the answer. A 2x4 is 2 inches of thickness by 4 inches of width, so you need to find the length, with 8 feet being the most common. You’d use the calculator here to multiply 2 times 4 times 8, and then divide by 12, arriving at a total of 5.33 board feet. 

Ultimately, overapplication of stain can compromise the deck's appearance, durability, and longevity. It may result in an uneven finish, with excess stain pooling, dripping, or drying into thick patches. It can also obscure the wood's natural grain and texture, detracting from the desired aesthetic. Moreover, excessive staining may not fully penetrate the wood, leading to poor adhesion and premature wear. Additionally, thick layers of stain are prone to peeling, cracking, and blistering as they struggle to bond with the surface.