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.

Waterproof paint creates a barrier to hold back moisture, but it doesn’t eliminate the source of the water. If you hire a basement waterproofing contractor, many will tell you that waterproof paint is only a temporary solution. On average, you can expect it to last from six months to two years in a wet basement before deteriorating.

Hiring a contractor or professional deck refinisher is the best way to ensure your deck is properly stained. They have the expertise, tools, and supplies to do the job quickly and efficiently. However, staining a deck is a manageable task for most homeowners, and doing the job yourself can save money. Just keep in mind that DIY staining is a long process requiring physical strain, so it may not be the best option for everyone.

Whether to brush or roll stain on wood depends on the project and your preference. Brushing is ideal for smaller, intricate areas and offers more control over the application, ensuring thorough coverage and penetration into the wood's grain. 

Conversely, rolling is efficient for more extensive, flat surfaces and can save time. However, it is not always the best fit for textured or uneven wood. Some projects may benefit from combining both methods, using a brush for detail work and a roller for broader areas. Ultimately, the choice between brushing and rolling depends on the specific requirements of your staining project.