Skimming loft walls and ceiling

There is often a debate between a line or a curve when joining from wall to skeiling (sloping section of ceiling, i.e. under pitched roof). The difficulty is that you can't use angle beads to get a perfect line, and doing by hand is much harder, especially if over a long span. Roof joists are rarely perfectly level and the stud wall would need to be perfect along the whole length too. The pitch of the roof can determine what looks best - a shallow pitch (more of an angle) is easier to get a straight line, whereas a steep pitch, and so less of an angle, is easier with a curved join. It is possible to get a straight line, but if you wanted it to be completely straight and level, expect to pay a bit extra as any plasterer would have to level out any un-squareness of the stud wall and roof joists.

I would always suggest to do a curved ceiling/sceiling as is probably the best outcome by far, you could plaster and create a straight ish line but without days of making it perfect it will not look good at all.. to give yourself a straight time to paint to I would tak your time and use frog tape and a penciled measured too make it even right around.

If the customer has asked for square angles the plasterer can give two of the costumerestimates baring in mind the level and Straightness of the plaster boarding, thenThe Boards would need a levelling coat of bonding plaster before finishing coat, Subject to the costumers budget then Yes to curved angles

I would Ames Tape it as you can either put the Metal Tape outsides in or use what we call the Tennis Bat and round them which looks a lot better. Yes its not easy for the Painter but it is better than looking at wavy lines