After patching refractory with plastic firebrick, holes are poked in the patch on 1 1/2 inch centers in order to __________.

Correct Answer: Option D — vent escaping moisture

Venting holes punctured on 1 1/2 inch centers through newly installed plastic firebrick patches allow trapped moisture to escape safely during the initial dry-out firing process, preventing steam pockets that cause spalling and catastrophic refractory failure.