Hi, We want to tile our porch walls about 1 metre high in old victorian style. The area is quite small (about 1m wide), and between two doors (front door to street and second door to house). At the moment there is some old flaky/cracked paint on the walls, under which there is a dark layer or something which seems slightly sticky - see picture. Can anyone recommend what we should do to prepare the walls before getting the the point of putting on the tile adhesive and tiles? What kind of products should we use to do this? Not sure if we need to strip all that paint off or if we can just use a primer (or both). The last thing we want it to put all the wall tiles on and they fall off because we put them on top of old paint! Many thanks in advance for any help.