It now looks like it will cost more than $4 million to repair the structure of The Leisure Centre.
The structural remedial costs were first pegged at $831,000, but tests have shown more damage than expected.
City Facility Manager Mick Philips says there is excessive moisture because of a lack of proper ventilation.
Using chlorine as a disinfectant at first and later switching to salt also took its toll on the facility.
The community living committee will get a full report Tuesday, and will have to decide whether to continue with the renovation.
$11 million has already been approved to reopen The Leisure Centre as a programming pool.