FiremanT, this guy is a piece of work. His detector first appeared back in a previous post.
FWIW: He was correctly advised by myself & others how to lower a bit of brickwork with hand tools but, no way, your man's determined to cause himself grief by using an angle grinder, get this, because he didn't want any mess.
He also claimed that his c/breast had been built half way up the wall suspended above the floor?
Now, another howler, he takes comfort & advice from the contributor least able to give professional advice, the struggling DIY'er nigel, who wrongly calls threaded steel pipe -"screwed iron pipe"
used in "Houses in the 60's" - wrong again because copper was used from the 1950's on.
Where would jobbing plumbers find liquid bitumen to pour into pipe chases - this I have never seen. Even bitumen coated pipe was mostly only used underground in domestics.
OP, who and where was "ripping the plaster off" suggested?
You were advised to carefully and gently remove plaster & skirting - watch my lips: do any of my words spell ripping?
Really good to know that someone knows what they are talking about. And even better when an OP has the courtesy and good manners to thank and acknowledge all who contributed to his thread - just saying.