Deck safety starts with a good design, and that starts with understanding building codes.
The 2015 IRC (International Building Code) states clearly that decks are not to be attached to cantilevered joists “Band joists attached by a ledger in accordance with Section R507.2 shall be fully supported by a wall or sill plate below.” Remember that every single code has a tragic backstory.
So what does that mean?
You know what cantilevered means, right? It’s when a room sticks out over a yard, without a wall underneath. There is usually no problem with the room itself. The trouble starts when you attach a deck to that room. The weight of the deck and the people using it are more than the building was designed for.
If you want to see a YouTube of deck disasters, you’re in luck. There are a lot of them. That’s because at weddings and graduations, someone with a camera says “Hey, everybody! Come out on the deck for a picture!
The solution is simple; add more support at the house side. This will create what is essentially a free-standing deck that happens to be attached to the house.