Haydn Skeleton Caulking Gun
Measure the width and length of the attic ladder. Then determine the centre point in your hall for the ladder. Measure half the width of the attic ladder from the roof centre line to one side. This will be where one side of the cavity is. Repeat the process at the other end to get a clean line for the opening edge. Use a level to join the marks for your first length line. Repeat the process on the other side then mark out the lines for the ends of the cavity.
Cut along the lines with your plasterboard saw, making sure there are no cables or pipes in the roof where you are cutting.
Work out whether you need to remove any ceiling joists in your cavity. If you do, make sure they aren't load bearing. Measure and cut noggins, which are horizontal pieces of timber around the frame, and fix them to the bearing boards. This will reinforce the area and prevent the ceiling from sagging.
Get someone to help you put the ladder up into position. Temporarily brace the ladder by hammering some scrap pieces of timber into the roof at each end. At the far end, nail the timber over the edge to help you to hold the ladder in. At the near end, the block should only cover the frame and not the door.