Having started plasterboarding today I've realised I have some fairly basic questions.   I understand it's good practice to avoid lining up board edges with the edges of openings- much as you would do with the frame sheathing. But I can't do this unless I cut a board in half lengthways. Is it really a good idea to add an extra floor to ceiling butt joint (and a messy cut edge meets tapered edge joint, at that) just to avoid having a tiny joint above a door??   Secondly, how i