sink waste pipe slants wrong way

[cluglue]

under the kitchen sink is an almost horizontal waste pipe for the sink and washing machine.

only trouble is, it slightly slants back, (not down, towards the outflow). So water is collecting in the pipe under the sink. It's not a huge slant - you can only tell if you look carefully.

Is it a big problem ? I seem to keep going through washing machine bits.

View media item 84694

 

[Newboy]

Eventually you will end up with a blockage as the gunk will collect at the lowest point. In the meantime unless you raise the washing machine waste pipe up to the height of the sink lip, I suspect that some of the waste water from your sink will be backfilling the washing machine.