There are a number of potential reasons for ceiling plaster to come away from the above structural surface. Improper application using insufficient bonding, a leak, or prolonged vibration from an upstairs room can all cause a cave-in, which can appear disastrous and costly at first; however, once the root cause for the collapse has been identified and addressed, you may proceed with the following inexpensive repair, with no need to hire in outside help.
Note: This repair is best suited to repairing large ceiling holes: that is, holes best measured in feet, rather than inches. Smaller holes may be more easily repaired with special patching kits.
What You Will Need
For this repair, you will need:
- A measuring tape
- A sharp and sturdy utility knife
- A screwdriver and screws
- Ready-mixed joint compound
- A sanding block and sandpaper
Step 1: Preparing the hole
Using a sharp utility knife, cut away uneven edges to square off the hole; this will make things much easier when it comes to attaching the new plasterboard. Brush off any loose debris and measure the dimensions of the squared-off hole. Ensure that the now exposed wooden straps are a smooth and even surface, ready for the plasterboard to be screwed on. Plasterboard comes in many thicknesses, so measure the depth of the hole from the wooden straps to the surface of the remaining plaster. Purchase plasterboard approximately 1-2 mm thinner than this distance; this will minimise the amount of finishing work you will have to do later.
Step 2: Preparing the plasterboard
Usually, by this point, your ceiling would be ready for plastering; however, since the plaster on the ceiling is purely cosmetic and not structural, it is not necessary to plaster over the hole. It can now be repaired much more quickly, easily and inexpensively using plasterboard and a ready-mixed skimming compound, which will achieve an equally professional result. To begin, take the dimensions of the ceiling hole and mark these on your plasterboard before cutting to the required size. If this proves difficult, a paper or card template can be fashioned and put in place to ensure that a good fit will be achieved. Simply draw the outline of your template on the plasterboard and cut to the desired outline using your utility knife.
Step 3: Fixing the plasterboard and smoothing the gaps
You may require an extra set of hands for this step at first: have someone hold the plasterboard in place as you fix it securely to the wooden straps with your screws. Once the board is solidly attached, mix up your skimming compound following the directions on the packaging. Begin to smooth over the joins and surface of the plasterboard as directed, and allow to dry. Once the compound is set, finish the area by sanding off any rough edges to form a seamless transition between the old and new ceiling surface. You are now ready to paint the ceiling and the job is done, at a fraction of the cost of plastering. Good luck!