On 14 Sep, 16:14, "george [dicegeorge]"
wrote:
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.

[g]

If you don't need to get them out just plaster/cement up. If you do,
use intumescent seal. Comes in the same tubes as silicon sealant.
Expands when heated.