A lab and workshop upgrade that reduces the rebuild time of the wall by a number of seconds. Wall Rebuild will push all enemies out from the tower to ensure no enemies are trapped inside.
The Wall Rebuild lab reduces the rebuild time of your wall by X seconds. You unlock this lab in Milestones by reaching Tier 8 wave 10.
The Wall Rebuild workshop consists of 300 levels that each reduces the rebuild time by 2 seconds, for a total reduction of 600 seconds reduced.