The red fibre washers - such as those used to connect a toilet up to the
mains water feed, etc - am I right in thinking that they expand
slightly after installation? Twice over the last year now, when using
red fibre washers in a joint, once with a toilet cistern and once with a
new roof cistern ball valve installation, I've had a very slight 'ooze'
of water out of the connection, which has disappeared after a while.
Would this seem right to the expert plumbers out there?