David Bolton Concealed Hinges on Interior Doors: When the Invisible Hardware Choice Creates a Very Visible Problem at Rough Opening Time Why Concealed Hinges Punish Guesswork at the Door Prep Stage A fully concealed hinge is invisible when the door is closed. That clean, uninterrupted edge profile is exactly why architects specify them... concealed hinges door hardware specification fire-rated openings full mortise hardware interior door hardware Jul 1, 2026