A coving is a decorative moulding used to accentuate borders around the ceiling. The mouldings are slightly arched and therefore add a dimension to the borders unlike the regular flat moulding. Because of the dimension, coving corners are slightly trickier to cut. Coving corners are generally cut using a mitre box because it ensures accurate angles needed to fit into the corner of walls.
Place the coving in a mitre box making sure that the edges are flushed against the sides of the box. Place the coving so that the ceiling edge of the coving is flush against the bottom of the box.
Carefully align the coving to where the cut will take place.
Firmly hold onto the coving, as it has a tendency to move around due to its flexibility. But be careful not to exert too much pressure or else the coving will break.
Cut the coving using the middle slots to make a straight, 90-degree cut.
Angle the saw at a 45-degree angle to the right using the lower left slot and the upper right slot. Cut the coving and use the right side to make internal right corners and the left cut piece for external left corners.
Angle the saw at a 45-degree angle pointing to the left using the lower right slot with the upper left slot. Cut the coving and use the right side of the cut piece for external right corners and keep the left cut piece for internal left corners.