How can I stop the dripping from a concrete ceiling?
I don't know how well it works but there are companies that will drill holes through the concrete and then inject a waterproofing agent under high pressure. This is normally done for walls but I'd guess could work for a ceiling. It might even work better as for a ceiling as it won't sink down the wall outside.
If you search for &quot;concrete waterproofing injection&quot; you will find lots of companies selling the service and some reviews (good and bad). I've never done it. I looked into it a while back when I had a basement leak but I solved it another way.