Extra support for cast iron soil stack

[elmsoft]

I'm wanting to install a downstairs wc and therefore T into the existing cast iron stack. I'm a bit nervous about cutting out a section for the pvc branch. The supports look OK but I'm a bit of a woos.
I'd be happier to see a few big rawl bolts giving extra support while I cut it. Are suitable brackets available or do I just need to man up?

 

[Steelmasons]

All joints/collars will be caulked with lead , above branch will hold the weight of stack even if pipe nails have fallen out due to rotted out dowlings...

 

[denso13]

due to rotted out dowlings

Or dooks north of the the border, don't know what they call them in Wales...

 

[halfway]

Dhjffjgsbnjrdvjfzv in Welsh

 

[elmsoft]

Thanks for the reassurance.

 

[Terrywookfit]

Fookin good luck with that one !!