Before installing a deck, you must build a base for the deck to rest upon, often made of compacted soil or gravel. While gravel is an optional material, it helps with drainage. Some contractors also recommend installing a weed control membrane, which helps provide a solid foundation for the frame. In the case of an elevated deck, a pro will often lay down a concrete slab as a foundation. 

Most building codes require that spindles or balusters on deck and stair railings be spaced no more than four inches apart. This safety standard, often called the '4-inch sphere rule,' is designed to prevent small children or pets from slipping through the railing. A good way to visualize this is that a 4-inch sphere should not be able to pass between two spindles. For the same safety reason, the space between the bottom rail and the deck floor should also be no more than four inches. As a general guideline, professionals often install three balusters per foot of railing. However, since specific requirements can vary by location, it is crucial to check your local building codes to ensure compliance before starting your project.

Most building codes require that railing spindles (also known as balusters) on decks or stairs be spaced no more than four inches apart. This safety standard is often called the '4-inch sphere rule,' which means a sphere with a 4-inch diameter should not be able to pass through the opening between balusters. This rule is in place to prevent small children and pets from slipping through the railing. For the same reason, the space between the bottom rail and the deck or floor surface should also be no more than four inches. As a general guideline, professionals often install three balusters per foot of railing. However, since specific requirements can vary by location, it is essential to check your local building codes to ensure compliance before starting your project.

Deck stairs should have at least three stringers rather than two. The recommended minimum width for stairs is 36 inches, and the International Association of Certified Home Inspectors recommends at least three cut stringers to provide sufficient support on wood decking stairs of this width. Generally, stringers should be a maximum of 16 inches apart for wood decking and 12 inches apart for more flexible composite decking.