I have done a few of these as mill my own stuff.Like all timber need to be seasoned first ideally.The apoxy resin is stronger than the timber and super strong.You either love them or hate them is my experience.
I am doing an oak beam at the moment with a tint of red in it.I will take some...
Seen it many times,When i was a kid a certain super market bought a whole street up to gain planning for a new store but the local undertaker held out and they ended up build him a massive 6 bedroom house for a little 2 up 2 down and a pile on money. Its called business.
If your sewer is linked into a main sewer and supplying 2 houses on private land then yes he would need permission to access it. Speak to your water utility supplier as they own and maintain the sewers. Nobody can just come on to your property and start digging it up.