DIY- Patching up the ceiling plaster
Flaking and cracking plaster are relatively minor maintenance items, but when the plaster starts to sag or "belly" out from a ceiling, it indicates deeper problems that require your full attention
If you've got a damaged ceiling, whether it's cracks from people walking on the floor above, water damage from a leak or just bulging plaster from wear and tear, you need to act sooner rather than later before the damage worsens and the job becomes too big for you to tackle or the ceiling becomes dangerous.
First things first: wear the right safety equipment, including a dusk mask, goggles and a hard hat.
Taking a stripping or filling knife, start to gently remove the loose plaster. Once you can get your fingers inside the crack, very carefully pull away the loose plaster until you can see the wooden laths. Carry on until you reach the joists and all the blown plaster has been removed, as you don't want any plaster left up there that's not properly adhered.
Next, use masking tape to secure a sheet of newspaper over the hole, ensuring it's stretched taut. Now draw the shape of the hole onto the newspaper, remove the paper and cut out the shape so you've got a template. Put the template on a piece of plasterboard and draw round it.
On a workbench, cut out the plasterboard shape and smooth off the edges with fine sandpaper. Now you can hold the plasterboard shape up to the ceiling hole to see if it fits. You may need to make the ceiling hole slightly larger or the plasterboard shape slightly smaller, so there's a few millimetres difference.
Get someone to hold the plasterboard shape in place on the ceiling for you and then put a straightedge across it. This allows you to measure the vertical gap between the ceiling and the plasterboard shape and thus the thickness of packing required to make the plasterboard flush with the ceiling. You can use materials like plywood, hardboard or plasterboard for the packing, which you should nail to the exposed joists.
Check again that the plasterboard shape will be flush with the ceiling and adjust the packing if required.
Once you're happy with it, secure the plasterboard shape to the joists using plasterboard nails. Brush a PVA solution all over the repair, especially around the edges. When it's dry, fill the slight gap between the plasterboard and the ceiling with filler, which should be allowed to dry thoroughly.
Apply plasterboard jointing compound over the joint and then push jointing tape into it, before applying another layer of jointing compound. Smooth this over with a damp sponge, making sure you blend the edges. Once it's dry, you can sand it smooth and wipe it clean.
Now you're ready to redecorate. If you have some of the original ceiling paint left, use that. If not, you may have to repaint the whole ceiling.
A textured paint - there are lots of different ones on the market - will disguise the repair better than standard emulsion, but textured paint may not be the look you're after. Another option is to wallpaper the ceiling, though the paper will inevitably start coming off over the years.
If you are using a textured paint, apply it to the area you've repaired with a roller or brush, following the manufacturer's instructions, then paint the remainder of the ceiling. Use a narrow brush around the edges to create a neat join with the walls.
Some textured paints can be covered with emulsion and if this is the case with yours, paint over it with your chosen emulsion once it's dry.
By the end of it, you - hopefully - won't be able to tell that the ceiling has been repaired.
Quick Fix - short answers to tricky questions
Hairline cracks keep reappearing in the walls around my bay window. I've tried hairline crack filler but this doesn't seem to work for long. Is there another solution?
It may be that the slight movement of the house is going to keep causing small cracks and there's not much you can do about it. You should first try flexible filler, though. This doesn't sand well, so you need to get it right when applying it.
Push it well into the cracks and smooth it over with your finger, dampening it first if necessary. Once you've made the repairs as neat as possible, wait till the filler's dry and then paint over. If you're worried about the cracks, get an expert in to look at them.
First things first: wear the right safety equipment, including a dusk mask, goggles and a hard hat.
Taking a stripping or filling knife, start to gently remove the loose plaster. Once you can get your fingers inside the crack, very carefully pull away the loose plaster until you can see the wooden laths. Carry on until you reach the joists and all the blown plaster has been removed, as you don't want any plaster left up there that's not properly adhered.
Next, use masking tape to secure a sheet of newspaper over the hole, ensuring it's stretched taut. Now draw the shape of the hole onto the newspaper, remove the paper and cut out the shape so you've got a template. Put the template on a piece of plasterboard and draw round it.
On a workbench, cut out the plasterboard shape and smooth off the edges with fine sandpaper. Now you can hold the plasterboard shape up to the ceiling hole to see if it fits. You may need to make the ceiling hole slightly larger or the plasterboard shape slightly smaller, so there's a few millimetres difference.
Get someone to hold the plasterboard shape in place on the ceiling for you and then put a straightedge across it. This allows you to measure the vertical gap between the ceiling and the plasterboard shape and thus the thickness of packing required to make the plasterboard flush with the ceiling. You can use materials like plywood, hardboard or plasterboard for the packing, which you should nail to the exposed joists.
Check again that the plasterboard shape will be flush with the ceiling and adjust the packing if required.
Once you're happy with it, secure the plasterboard shape to the joists using plasterboard nails. Brush a PVA solution all over the repair, especially around the edges. When it's dry, fill the slight gap between the plasterboard and the ceiling with filler, which should be allowed to dry thoroughly.
Apply plasterboard jointing compound over the joint and then push jointing tape into it, before applying another layer of jointing compound. Smooth this over with a damp sponge, making sure you blend the edges. Once it's dry, you can sand it smooth and wipe it clean.
Now you're ready to redecorate. If you have some of the original ceiling paint left, use that. If not, you may have to repaint the whole ceiling.
A textured paint - there are lots of different ones on the market - will disguise the repair better than standard emulsion, but textured paint may not be the look you're after. Another option is to wallpaper the ceiling, though the paper will inevitably start coming off over the years.
If you are using a textured paint, apply it to the area you've repaired with a roller or brush, following the manufacturer's instructions, then paint the remainder of the ceiling. Use a narrow brush around the edges to create a neat join with the walls.
Some textured paints can be covered with emulsion and if this is the case with yours, paint over it with your chosen emulsion once it's dry.
By the end of it, you - hopefully - won't be able to tell that the ceiling has been repaired.
Quick Fix - short answers to tricky questions
Hairline cracks keep reappearing in the walls around my bay window. I've tried hairline crack filler but this doesn't seem to work for long. Is there another solution?
It may be that the slight movement of the house is going to keep causing small cracks and there's not much you can do about it. You should first try flexible filler, though. This doesn't sand well, so you need to get it right when applying it.
Push it well into the cracks and smooth it over with your finger, dampening it first if necessary. Once you've made the repairs as neat as possible, wait till the filler's dry and then paint over. If you're worried about the cracks, get an expert in to look at them.