Can i know what's the purpose of doing water proofing and water ponding test? What's the difference? I stay in condo. Is that necessary to do it together at the same time with unit owner at upper floor and lower floor?

I've collected the house key in December'22 but didn't start any renovation yet. Recently, i noticed that there's water mark at ceiling in toilet. I have filed that as defect to management given that I'm still under Defect Warranty Period and can make claims within 2 years if found any defects.

The lower unit already completed the renovation and have people staying now. Let say i'm doing water proofing test now, and found that the test is failed. If anything happen to lower unit owner's ceiling in toilet, can i file that as defect although he has already completed the reno, but I still didn't?

Doing water ponding test to see if any leakage through the tiles/floors of toilet. Seal the floor trap, fill with water and observed for a day see if water level reduce or leakage.
Still can claim defect from the developer...else if after 2 years period only found out water leakage, then lower floor can claim the repair damage from you. And you have to redo waterproofing.