I have used the following method on several retrofit homers with 100% success of:
Dont drill through the footings or wall !
Break out concrete basement floor approximately 18 " from the outside walls.
Dig out a trench to the bottom of your footing. (Below floor, 1' to 2' deep)
On the very first course of block, drill a series of Ύ" hole into each block cavity releasing any trapped water from within the block.
Install drainage board in front of drilled holes from the weeping tile trench up wall to just below the bottom of the floor.
Place 4" weeping tile (Fabric covered) beside your footing.
Inside weeping tile can now be hooked up to sump box or closest floor drain.
Excavated area should be covered with Ύ" gravel to just below floor level
Re-pour concrete floor leaving Ύ gap space at wall
A lot of work but well worth it. I never did understand why builders just did not put weeping tile and proper exterior sealing and drainage board on foundations.
Do not drill holes into a poured concrete wall.
To install an inside weeping tile system for a poured concrete foundation, the process is the same.
Drainage board will allow any water, that has gained entry, to freely drain into new weeping tile system..
1. Again, do not drill holes into a poured concrete wall or footings !
2. Do not dig deeper than the bottom of your footing.