The plastic in composite decking boards protects them enough that you do not need to paint them to prevent warping. In fact, painting composite decking voids the warranty of some manufacturers. Painting can also increase maintenance on the deck, as you must paint regularly to keep it looking its best.

Wood stain is not flammable after it dries. The solvent in wood stain is what causes the liquid form to be highly flammable, but the stain drying process involves the solvents dissolving, which leaves behind a non-flammable product on your wood project. Wood stain is, however, flammable before you apply it, so you should always store partially full cans and used wood stain rags away from sources of heat and open flames.

Hangers are one way of attaching stair stringers to a deck. These metal hangers are usually adjustable, allowing you to find the ideal angle for a secure installation. They’re the best choice for installing longer staircases, such as one on a two-story deck, to reduce the load on the deck frame while keeping the stairs stable.

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.