Sherlock looks down, like he hadn't thought about it. (He had, but things like that aren't important to his conscious mind at this moment in time.)

"Seems structurally sound. For now." He swipes a finger along the underside of the hand railing as he goes. "Probably best not to put it under any extra stress."

He flashes a grin over his shoulder. Oh, this is excellent. "Can't make any promises, though."