The felt is not strictly your roof weathering .
If your roof is in good order then it won't need felt to keep the rain out.
If you have water coming through the felt then the roof is leaking .fix the roof
we have had fabricated alloy box gutter at 11 mtr. biggest issue might be transport
When was the picture taken?
The outside picture shows approx 10 courses at the bottom of the roof a slightly different shade.
Looks like tiles missing.
The battens are showing through but light showing in between..
Looks like half the roof .
Get some pictures from...
The upstand can be formed around the pipe simply enough . Then weathering collar, and mushroom oraor cage normal. Nothing needs to bond to the pipe
We have come across plenty of designers that spec materials and systems that are wrong for purpose or long winded or even just poor practice....
or glass the pipe in
put a gutter round
The undercloak is for a mortar bedded verge. Much like you have now
there are other products for dry verges , no mortar. They tend to be plastic...
yes plastic shiplap, or maybe fortex or...
i see two rooves. One which I guess you are cladding the end. id use proper ship lap or similar. hollow might be a bit weak
concrete tiles are...
Need to calm down and you might get a reply
If it's 15 then follow the instructions
It's easy enough
It's your choice , 75 mm is within realms of good lead work
A very important thing is chase the joint out well.
red looks like 75 mm? in which case its fine
Probably a plastic dpc, these have uses but not in a parapet with copings.
The coping is a dpc its self to a point. But not long term reliable .
wrong flashing kit used. should be an EDL (for slate) this is possibly edz or edw (for tiles)
Tell him its the wrong flashing kit and get it...
if you are familiar then you will know in this situation it will stop the moisture entering the brickwork , solid or cavity
using a plastic course...
Separate names with a comma.