Hi @Sam12,
Many thanks for your question.
There is absolutely a way to patch this that won't crack unless there is major movement in the wall.
To repair this hole, you will need to pick up 3 things from your local Bunnings store. A Gyprock CSR 1.5kg DIY Rapid Plaster Repair Kit, a piece of 64 x 19mm 1.2m DAR Pine Standard and some Zenith 8G x 25mm Gold Passivated Bugle Head Plasterboard Screws.
Start by cutting the timber so you have 2 pieces approximately 100mm long. These will be slotted through the hole and fixed to the back of the plasterboard through the existing plasterboard using the screws.
These timber pieces will act as a backing piece that your repair patch can be attached to. In plastering, this is called back blocking and is used frequently to make patch repairs where studs aren't available.
A tip to get them into place is to put a temporary screw in the timber to act as a handle while positioning them.
Once positioned, screw through the existing plasterboard into the timber at least 25mm from the side of the hole to prevent fracturing. Being careful not to over drive the screw as it can pull through the face of the plasterboard.
Once your back blocks are in place, measure and cut a piece of the Gyprock repair panel that will fit nicely in the hole. This can be done by scoring the paper face of the plasterboard with a utility knife, then snapping it and cutting the back of the board. You might like to check out How To Plasterboard a Stud Wall for an example of how this is done. Make sure you secure the repair patch in place with at least 4 screws to get a good connection and to prevent any movement.
Once this patch is in place, use the mesh tape provided in your plaster repair kit to cover the gap between the new and the old plasterboard. This tape gives the plaster compound strength and will help prevent cracking in the future.
Once taped, apply the plaster following the instructions in the repair kit, then sand smooth before painting.
You might like to check out How To Patch Plaster for a visual guide on how to go about this repair.
Let me know if you require further clarification.
Jacob
