Project Overview

The cornice is an important finishing detail in your room. We show you how to cut your cornice pieces so they fit neatly together in internal and external corner joins.
Continue to Step-by-step instructions.

Step by Step Instructions

1 How to cut an internal corner
2 How to cut an external corner
  • Step 1. How to cut an internal corner

    The plasters mitre box has three different levels for cutting different sized cornices. We have used a 45-degree angle and a 55mm cove. For an internal corner cut, make sure the cornice is secure in the box by holding it in the groove. Use the mitre box guides to cut the cornice at a 45-degree angle. The finished piece will look like a V. When you turn it upside down and join it with the other piece it fits into an internal corner.

  • Step 2. How to cut an external corner

    For an external cornice cut, secure the cornice in the box and use the external corner guide to cut a 45-degree angle.  The external cut is made at the same angle, but in the opposite direction to the internal cut. When you turn it upside down and join it to another piece you get an external corner.

Please make sure you use all equipment appropriately and safely when following the advice in these D.I.Y. videos. You need to be familiar with how to use equipment safely and follow the instructions which came with the equipment. If you are unsure, you may feel it is safest to consult an expert, such as the manufacturer or an expert Bunnings team member.

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