If the wall in my basement is leaking very slightly, is the main/only solution to the actual water issue to add grading outside? What else?
It is under a deck, which I can rip up a bit and fill with dirt, but is that likely to solve it?
We noticed from slightly bubbling paint and efflorescence.
Grading is not your only solution but it is the only economical option with a great success rate. You very quickly dive into catastrophic costs when upgrading to a French drain or coating the exterior of the basement wall.
I’ve had the issue you’re describing and solved it both times by adding fill dirt at the wall, grading the pitch away and laying heavy mil plastic that I tucked and fastened under the deck’s ledger board. I was able to work under one deck but for the other, I disassembled it then put it back together when finished.