I'm still unsure exactly what the best thing to do is. I've got some photos now and made a small bit of progress as I've removed the existing plasterboard ceiling and put the injection dpc in. Whether it's needed or not, the cost wasn't too much for me to do myself.
I've spoke to the guys who sold me the dpm and they suggested tanking the bricks below the dpc. Trouble is with paint on them I can't and I understand tanking isn't always a great idea.
In the photos any dark patches on the floor may be as there was a large wooden station with shelves here before and soiled spilled from potting happening before we bought the house. I've since cleaned the area and the water does pool towards the back left corner.
The wall with the shovel on is the one with neighbours soil about 3 bricks from the bottom in height. The others have the outside patio about 2 bricks from bottom.
If I put an air brick in the shovel wall, what position should it be roughly?
The plan I think I've decided is the follows.
Put an air brick on that rear shovel wall.
Lay 1 course of bricks spread out on the floor put the dpc sheet down and then lay another course of bricks on the original to create a gap below the dpc for air flow and allow the floor to be drilled into something.
Then put the egg shell style dpm I've got on all the wall going up to the ceiling.
Then timber drills onto that. Then insulate in between.
Then for the ceiling, figure out how to close up the gap that the plant is coming in (though perhaps air flow here isn't a bad thing?) then insulate the ceiling.
Should I lay a dpm between the layer above the ceiling and insulation, or between insulation and plasterboard, or not at all?
Then plasterboard everything and chip board the floor.
Any issues with this?
If I can ill try remove the soil from neighbours wall and apply blackjack to the lower part of the exterior wall.
