Hi I've stripped back to the bare brick on a small toilet room, which I intend to tile over after plaster boarding. The problem I have is the walls are very uneven, my question is how do I make sure the plaster boards are level with one another and plumb? For plumb I'm guessing its start from the high point and fill out the low points with more adhesive. I'm not sure how to level the boards with one another so that they are flush and inline. I'm guessing it's all in the setting and marking out to get everything squared off, so if someone could enlighten me as to how this is done correctly it would be a big help.