Antonyms for the phrase "break deck" include terms like reinforce, fortify, strengthen, brace, bolster, and secure. Each of these words describes actions that serve to make something stronger or more stable, rather than disrupting or destroying it. To reinforce a deck, for example, might involve adding extra supports or replacing weak boards, while securing it could mean installing safety railings or fixing loose nails. The opposite of breaking a deck, then, is to take steps that ensure it lasts for a long time and holds up to wear and tear.