Thks guys for the advise. The HDb officer said , if I don't do it soon, I might spread to the neighbour below my neighbour ? Is that even possible ? It's just that I wasn't given any proper documentation to justify the cause is indeed from my toilet. My mum has the same problem , when she consulted HDB , they said it wasn't the upstairs neighbour fault and not HDB fault as well. So who's fault ? Kinda weird huh ? Anyways , thank goodness my ID is still with the reno company and he took a look at my toilet just now. And he told me that all the pipings were installed by following HDB guidelines. Went to neighbour's hse, but they were not home. My ID said if confirm it is indeed from my unit due to their worksmanship or error, they will bear the cost.Coz my warranty is for 5 yrs . PHEW ~~ I hope this can be over and done with coz I don't wish to create any unplesantless to my neighbour too.Plus Hari Raya is around the corner...cialat !! I wld hate it if it happens to me too.