"DerbyBorn" wrote in message
2.222...
I need to bore a hole in a joist to take a shower waste. Reading the regs
tells me that in a 20cm Joist the max hole can be 32mm

I need to pass a pipe of 42mm diameter!

The joist is right next to a wall at the outer edge of the house - load on
it will never be high.

Pragmatically - would you go ahead and bore the hole?

go on take a chance ...all the other joists and flooringwill stop anything
bad happening.......