Indeed it is. ? I’ve found the scorer ok but as you say, needs numerous passes. Otherwise I’m using a track saw with a 4 tooth blade, attached to a knackered old Vax (some improvement needed there maybe) ? ? Im using a jigsaw, seems to be working ok (slowly of course) ? ? Noted. I’m in too deep to stop now so wish me luck.?
The bath end panel has tiles stuck on 12mm marine ply with CT1 Grab & Bond. The "grout" is in fact Everbuild Forever white. That covers the screw holes also. Easy to cut out. You can see the join at the two halves of the bath frame: ? ? Similar trap access from the side: ? ?
"300 hi load dpc" noted, I will check that out. ? Looking at your photos I get the impression the dpc sandwiched under the block has a short 100mm to 200mm flap hanging down and this short flap is then lapped with a second wider intermediate section that takes the dpc down to the floor where there will be a second lap to the main DPM on the floor.