Hi Daryl: Yes, I'm afraid so. The logic here is simple. Hydrostatic pressure will continue, 24 hours a day, 365 days a year. It won't give up and it won't go away. Anything you put on that wall, from a thin coat of paint to 4" of mortar will eventually be "pushed through" by the hydrostatic pressure....its just a question of time. Use Mother Nature's laws.....its the only sure way.