Decks greater than what height above grade should have diagonal bracing?

Diagonal bracing is essential for maintaining the structural integrity and stability of a deck, particularly as it gains height. When decks are elevated, they face increased risks from lateral forces such as wind and seismic activity, which can lead to swaying or shifting.

Decks that exceed 6 feet above grade are particularly vulnerable to these forces, making diagonal bracing a necessary element in their construction. This bracing helps distribute load forces and prevents the deck from moving laterally, ensuring safety for occupants and reducing the likelihood of structural failure.

The code and best practices suggest installing diagonal bracing at this height threshold to adequately support the deck's weight and protect against environmental factors. This measure becomes increasingly important as the height increases due to the greater moments and leverages involved. Therefore, the requirement for diagonal bracing at decks greater than 6 feet above grade is rooted in safety standards and structural engineering principles designed to mitigate risks.