Clogged bathroom hand basin

[BritinPh]

ExPat Brit living in the Philippines. I have an American standard hand basin installed in the bathroom - Single cold feed, with a popup plug - Problem the first part of the P trap clogs with a black mass from time to time easily cleaned via the clean out port. - Question is, considering the only use is for my infrequent shaving and regular tooth brushing and hand washing nothing else goes down the basin. Is it because of the cold feed only that the clogging occurs?

 

[Deleted member 120897]

Perhaps there’s been a previous homeowner/tenant? Or is this a new installation?

 

[BritinPh]

Perhaps there’s been a previous homeowner/tenant? Or is this a new installation?

No this is not new, about 5 yrs old a new build

 

[Deleted member 120897]

Might just be solidified soap etc. Try pouring boiling water down the drain, along with soda crystals, or bicarbonate of soda.