There are three main levels of plasterboard repairs. We will describe them as dents, holes and wrecked.
These are usually caused be bumping the wall while moving furniture or kids playing. There a number of products on the market for filling plasterboard, they are simple to use and can be done by most people. The main thing to do is ensure your trowel covers the whole area so you can get a smooth finish. You may have to do a couple of fills and that is far better than over filling and have to sand back. Sanding is necessary to get a smooth finish, but in this case less sanding is always better. Be warned plaster dust goes everywhere and clogs the sand paper in record time. Once you are happy the wall is again smooth you will have to paint it. You must seal and undercoat the patch before repainting the wall colour. Make sure you feather out well past the patch, match the colour and again feather the paint well past the undercoat. Depending on the colour match and the age of the original paint, you may have to repaint the whole wall to get a good coverage
Holes are when a complete piece is missing and can be repair with one of the many patches available. Make sure the patch covers the complete hole and overlaps onto the existing wall be a good 20mm. Theses patches are self adhesive and are plastered once in place. Follow product instructions and then paint as detailed above.
There is no way this type of damage can be filled. This is the type of repair that Ken the Fixit Man your fast and reliable handyman in Toowoomba, will do. If you want to try yourself, you will need to locate the supporting studs either side of the damage. The sheet will have to be cut down the center of the stud either side of the damage. Before cutting across the damaged sheet, carefully remove some plasterboard so you can see inside the wall. you don’t want to cut any pipes or cables. Use a hand saw, not a power saw to make you don’t damage anything. Once the hole has been opened you will need to install timber between the studs on the top and bottom of the opening. The timber needs to be installed so it will support both the existing and new sheet. Cut a new piece of plasterboard to fit the opening, screw into position. then plaster the joints as detailed for patching a hole. This is a very big plastering job, don’t rush it and be sure to install in small layers and remove any excess amounts so there isn’t too much sanding. Sand the patch between each layer to ensure a smooth finish.You will have to use the wide curve trowel to make sure the joints are completely covered and the joints are hidden. once plastered then paint as detailed above.