Level surfaces and clean looks can be harder to accomplish than it might seem, especially when you’re building a deck over a living space. The subject might seem overly particular, but properly designing a deck over living space demonstrates architectural sophistication and consideration to the design process. It’s also a piece of the architectural puzzle that should be tackled early on in the design process, as it has many dependencies. One way it’s trickier is that decks need to slope to drain. This typically requires that the structural joists are tapered, or that there’s an additional layer of non-structural tapered joists (or sleepers as they’re sometimes called). Either scenario usually requires additional depth.
Read the entire article here: Smart Ways to Build A Better Deck