Damp refinished basement

[Tim McCahill]

The ground floor of my duplex apartment is below-grade and has experienced water infiltration. I only recently bought the property and have repaired the leaks I can identify, but one appears to be coming from the outside entryway of a neighboring attached building - essentially, the entryway is badly graded, causing water to pond in the area where the building meets mine and penetrate my basement. It's uncertain whether this area will be repaired and I'm looking for alternative solutions, like waterproofing the party wall from inside my basement. Has anyone done this before? What were the results? Thanks.

[Michael Gessner]

If I may add, Never by no means ever waterproof or try and correct the issue with interior drainage systems, think about it your still allowing moisture in the basement, if anything now your increasing moisture from entering into the dwelling because now you just exposed below the foundation floor, its a cheap way of putting a i guess you can say band aid on a more serious issue. Its an incorrect way to resolve a problem. Ive done many foundation water proofing jobs where contractors came in and did perimeter drains, to only call me in years later to do what should of been done from the beginning.  Always correct the issue from out side.

1st how old is the house, you say the walls are damp, well do you have gutters on all the roof lines, you be surprised how many damp basements get fixed by cleaning your gutters or making adjustments, where are the gutters dumping? are they dumping at the foundation or piped away from the house? If you were getting moisture through the floor then I would suspect footing drains need to be replaced or may need sump pump. Many different variables but id start with the gutters, next id check is whats the grade of the yard, is there any surface pitched towards the house, is there a patio, you'd be surprised how many contractors don't know how to use a level when installing a patio