Water against the foundation
Saturated ground pushes hard against a wall. Relieving that pressure is a drainage job, not a waterproofing job.
What's actually happening
When the soil beside a foundation wall fills with water and can't drain, the water pushes against the wall and finds any way through: a joint, a tie hole, a crack. Sealing the inside of the wall doesn't lower that pressure. It just moves where the water shows up.
Interior sealing treats the wall. Exterior drainage treats the cause.
What we'd look at
Grade at the wall
Whether the ground slopes away from the building or toward it.
Footing drain condition
Present, missing, crushed or silted up. Often that's the whole answer.
Backfill
What the wall was backfilled with, and whether it drains or holds water.
Discharge
Where the drained water will go, by gravity where possible.
The likely fix
Installing or replacing the footing drain, backfilling with material that drains, and giving the water a route out. Where digging along the wall isn't practical, a curtain drain uphill of the house can often take most of the load.
