The reliable way to hire a tradesperson

Hello. Does redoing a roof fall within the scope of the Party Wall Act 1996? Considering the fact that the during the works party wall will be exposed and the neighbour's roof will be partly stripped off in order for replacing lead adjoining gutters, is serving a Party Wall Notice 2 months in advance and getting a written consent from the neighbours what I really have to do? Or not? The information is contradictory even on professional sites. How does it work in real world? Thank you

Hi some advice please. I've had damproofing completed by a firm I got on here with good reviews however he has left 2 bricks out of the internal wall just above the subfloor and says they don't need to go back. Surely this is not correct ?

Local water company fitted a meter to my property, obviously they shut the water main off, since then the cold water tank that supplies my non-combi boiler won't fill, the float valve is operational but the tank won't fill and so I don't have hot water. I've tried the airlock fix of back flow through the kitchen mixer tap but it's not worked, any ideas?