Bath Waste pipe

[akey]

We are currently installing a new bathroom however the new bath plug is at the other end of the bath from the original one. This gives me 2 problems, the first is that the waste pipe run will need to be 2.5m to reach the existing soil stack. The second is that I would need to cut through a number of joists to run the new pipework.
Is this permissible or will I need to install an external waste pipe?

Any ideas would be much appreciated

[peter the plumber]

The simple way to do this is to raise the bath or turn the bath around.

You can’t cut joist to 44mm they will not take it.