Tap Connectors Fibre washers

Problem always leak eventually?

Ok just replaced those dam fibre washers in the 2 kitchen sink taps and now
the bathroom basin hot tap also beginning to drip (Bathroom basin tap less
than year old).



I am sure I fitted them correctly just finger tight then tighten just enough
to stop water leaking (being carefull not to overtighten). Anyone else find
the fibre washers dont last long,
anything I am doing wrong or is this a common problem with fibre washers?




BES page 150
Tap Connectors
Female copper x BSP union nut Washer included