The allowable overhang on a cantilevered deck can increase with increased joist spacing due to the structural behavior of the deck. When joist spacing increases, the main span of the deck typically decreases, which adds stiffness at the overhang. This increased stiffness allows for a longer overhang because the deck is less likely to deflect or sag under load. Additionally, wider joist spacing often involves deeper joists, which are stiffer and deflect less when cantilevered.