"george [dicegeorge]" wrote in message
...
I'm knocking holes through walls to put wires through,
mains electric and ethernet.
I've been concreting in offcuts of round plastic drainpipe.
How would I seal these against smoke and fire?
Is there a better way to do it?
Someone said using metal would cause induction.

How much of a seal do you need?
These no good?
http://www.wickes.co.uk/Single-Gang-...te/invt/204733
http://www.wickes.co.uk/Double-Gang-...te/invt/204734