Solid ish. You need to make sure it is solid and all joints are picked up and there is no flex before putting down the membrane. Ceramic tiles and movement are not good
You will need to remove all the old Adhesive and any loose plaster, 6" scraper would be best. Then smooth out the missing areas. It is much easier to tile on flat surfaces as you get a consistent bed depth
If you could buy experience it would be sold out everywhere. You will get quicker with time as you learn what needs to be perfect and what can be worked round. Dont skimp on prep work even if it seems like you are going backwards, it will save time later.
Take time at the beginning of the job...
Most installs I use plaster board and tank the wet areas. I find it's easier to dry line with the larger boards.
As I do full installs floors are 25mm ply with detria. Or 18mm ply and 6mm Jacko board
Each job has to be judged on time on an individual basis. Level of finish, type of tile, wall construction, first second or third floor stairs add time. Parking all these thing have to be taken in to consideration
Are you removing the tiles? If you expect them to be removed then it's best to go and look when removed and then firm up your quote. If they are unhappy with a revised quote for extra prep work then walk away.
I always put a paragraph in my quote detailing the cost of worst case. e.g. all out...
I would have a full height screen 600mm with a 300 flipper on the end to keep the water in. Would also have under floor heating. Have you checked you have sufficient fall and drainage to cope with the shower flow
Not unusual to see block work in that condition.knock the rest of the plaster and bonding coat off then dry line with plaster board dabs at 300 centres. Skrim and fill the joints. Nice flat level walls will gain the time spent prepping the walls back when tiling
Tiled on to paint. Adhesive cures and shrinks then the paint bond to the wall breaks and the biscuit of the ceramic tile then can't take the sinking and cracks and bows the tile. This is made worse if the bed depth is thicker.
If the floor is flat then it will be around 22mm. A carpet and underlay up to the tile will be between 16 an 20 mm depending on the carpet. If you trim the tile edge across the door way a slight difference will not notice.
It's a pain to cut and screw to the joists.
It's very brittle.
Light weight foam core boards are much easier to use and are water proof when joints are sealed correctly.
I have approx 100m2 over 3 rooms to strip back the old adhesive and fleese backing left by the detria mat.
It all has to come up as I need to meet and existing floor in one door way.
What would be the best machine to assist me in this task.
Many thanks
David