Restoring Plastered and Plasterboard Walls – 4 Common Problems Solved

Restoring Plastered and Plasterboard Walls – 4 Common Problems Solved

. 7 min read

Interior walls can easily make or break the overall look of a room. Cracked plaster can distract from even the most beautiful décor, peeling paint can make the most spotless room look unkempt and even minor eyesores like stains and marks can make a room appear unfinished and unrefined. Luckily, most interior wall woes are easy to rectify with some simple DIY. In this article, we look at four common problems homeowners face with plaster walls and show you how to overcome them.

How do I know if a Crack is Cause for Concern?

Cracking is a very common issue with plaster walls. Usually, plaster cracks are not cause for concern as the damage is generally cosmetic. However, if the crack is particularly large and goes off in a diagonal rather than horizontal or vertical direction, or continues to expand/widen this could indicate a serious problem. If you are concerned about a crack in your home it is best to call for the help of a professional such as a building surveyor or structural engineer.

Sometimes cracks can be caused by a leak. These are pretty easy to spot as there will be staining or discoloration surrounding the crack. If you have a crack caused by a leak, you will first need to rectify the source of the problem by identifying the source of the leak and repairing it, either by yourself or with the help of a professional plumber.

Repairing Cracks

Suggested Tools:

  • Utility Knife or filling knife
  • Paintbrush
  • Joint filler
  • Joint knife
  • Spray bottle or sponge
  • Dust Mask
  • Safety Goggles

Step one: Score the crack

In order to properly repair the plaster crack, you will first need to widen its edges. This will help the joint filler adhere to the area and provide a seamless result. This process requires a methodical approach and a careful hand. Use your utility knife or filling knife to gently scrape into the crack and open its edges. Do this for the full length of the crack. The tool you use will depend on the width of the crack. A utility knife will help to gently score a hairline crack whilst a filling knife will be more useful if the crack is slightly larger. Remember, before cutting into the wall, first check for cables and pipes using a cable and pipe detector.

Step Two: Remove debris

Scoring the crack will cause dust to settle inside it. To get a professional result, you will need to remove this. To do so you can either use a shop vacuum or an old, dry paintbrush to dust inside the crack.

Step three: Dampen the wall

Dampening the area you are working on will prevent the joint filler from drying out too quickly, which in turn will help you work at a steadier pace. You can dampen the wall by spraying water onto it with a standard spray bottle or pressing a damp sponge onto the wall.

Step Four: Apply the filler

Mix and apply the filler to the crack using the joint knife. You will want to use a scraping motion with medium pressure so that you are pushing the filler into the crack and scraping off excess so that the wall appears flat. You don’t have to be too precise here as any slight bumps in the filler can be smoothed down with sandpaper afterwards.

Step Five: sand the wall

Once the filler is completely dry, sand over the area using a 220 grit sandpaper. Now you can paint over the area.

Chips and Chunks of Missing Plaster

Suggested Tools:

  • PVA adhesive
  • Plastering trowel
  • Filling Knife
  • Plastering hawk
  • Paintbrush
  • Course grit sandpaper (80-100)
  • Medium grit sandpaper (200 – 300)
  • Plaster (pre mixed or bagged)
  • Dust Mask
  • Safety Goggles

It is almost inevitable that at least one wall in your home will become knocked at some point, and the plaster will become chipped. DIY and domestic accidents can also cause plaster to come off in larger chunks too. So if you’ve been left with the job of repairing those chips and chunks, here’s what you need to do…

Step One: Remove loose plaster

Piling on fresh plaster to old plaster that is crumbling off will only make your problem worse. So before you start use a utility knife or chisel to remove any loose or crumbling plaster. This may make the chunk bigger, however this will be covered with the fresh plaster. Before cutting into the wall, check for pipes and cables with a detector. Once you have completed cutting and reached solid plaster, brush over the area using a dry wallpaper paste brush or paintbrush.

Step Two: Apply PVA adhesive

Use a paintbrush to apply PVA adhesive to the area. Apply it to the damaged area itself and slightly on the wall surrounding it. This will help the fresh plaster to stick to the area for a solid finish. Leave the adhesive to become tacky but not dry before applying the plaster. If you are mixing the plaster yourself, you may want to do this as the PVA is drying.

Step Three: Apply plaster

Scoop the plaster from its bucket using the trowel and add a dollop onto your hawk. Smooth the plaster onto damaged area, working from the hawk to collect a generous dollop of plaster each time. If you are working with a very old wall you may notice behind the damaged area are wooden laths. To avoid the plaster falling between the laths you will need to start working from the outside of the damaged area inwards, using a good amount of plaster. For more modern properties, starting in the centre is fine.

Step Four: Smooth the plaster

Use the trowel to smooth the area so that is flush with the wall.

Step Five: sand

Once the area is completely dry, sand it first using a course grit paper to remove larger ridges and bumps and finish it off with a medium grit paper for a seamless finish. Your wall is now ready for a fresh coat of paint or wallpaper. If the area requires a lot of sanding and you are creating a lot of dust, be sure to wear your dust mask and goggles.

Holes in Plasterboard

Suggested Tools:

  • Scrim tape
  • Gypsum based Joint compound
  • Filling knife
  • Sandpaper/sanding block 100 – 150 grit
  • Utility knife
  • Plasterboard saw
  • Pipe and cable detector
  • Spirit level or t-square
  • Tape measure
  • Drywall screws
  • Cordless drill/screwdriver
  • Wooden lath (around 25mm x 25mm)

You will need a square of Gyprock or plasterboard (the same thickness as existing board). The square of plasterboard will need to be cut larger than the hole you are repairing.

Holes in plasterboard walls require a different repair process to holes in plastered walls. Whilst plasterboard offers its own set of benefits, it can also be easier to damage than plaster, however repairing it is a simple process with the right know how.

Step one: Draw around the damaged area

Start by using a pencil and spirit level/t-square to draw a square/rectangle around the damaged area. The edges of the shape should be approximately 200mm (2cm) away from the edge of the damaged part.

Step two: Score the square

Use your utility knife to score the lines you just drew. This will help when it comes to cutting the board with your drywall saw. At this point you can also draw diagonal lines from each corner of the square/rectangle so that they cross in the centre. This may also make this easier when it comes to cutting the drywall with the saw.

Step Three: Cut out the square

Before you make any cuts into the drywall, use your cable and pipe detector to check for any potential wires/pipework behind the wall. Then, begin cutting into the wall using your drywall saw. Using the lines have drawn as a guide, you may want to start from the hole itself and cut outwards towards the edges of the shape, working in sections. Alternately you can just saw directly into the edges of the shape.

Step Four: Create a backing frame

Now you will need to create a frame within the hole for your patching piece to adhere to. There are several ways to do this but the most common is to lay wooden lath horizontally behind the hole and secure it with drywall screws. Cut the lath so that it will overlap each side of the hole by around 1-2cm. secure one lath at the top and one lath at the bottom of the hole. If the hole is particularly large you may one to add more strips in the centre. When drilling into the drywall, take care not to break the face paper with the screws. The screw head should be flush with the drywall.

Step Five: Cut and place the repair piece

Cut a piece of plasterboard to the exact size of the new hole. Push the piece into the hole and secure it to the laths using drywall screws.

Step six: Seal the joints

Apply the scrip tape to the joints between the new piece of plasterboard and the original drywall. Apply the gypsum based joint compound to the tape using your filling knife. Make sure the joint compound overlaps each joint by at least 2cm on each side. Once the wall is fully dry, sand and add a second layer of compound covering a larger area at least 5cm larger than the original patch.

Step seven: Sand

Once the area is completely dry lightly sand so that the repaired patch blends in seamlessly with the rest of the wall. The area is now ready to be painted or wallpapered.

Screw holes

Suggested Tools

  • Utility knife
  • Cordless drill/screwdriver
  • Filling knife
  • Jointing/fill plaster
  • 100 – 150 grit sandpaper or sanding block

Although they’re small in size, plasterboard screw pops are pretty annoying. This is especially true when the plasterboard doesn’t just ‘pop’ away from the screw but actually falls off and leaves you with an unsightly crater. Thankfully, fixing the issue is a fairly easy and simple process. Below we show you how.

Step One: remove loose plaster and paper

Use your utility knife to remove any loose plaster or paper around the screw.

Step Two: remove the screw

Screw pops are usually caused by the shrinkage or contortion of timber studs. However, if you find that screw pops keep occurring in the same places even after repair, this could be down to the fact the screw has penetrated the lining paper of the drywall and needs to be removed. For best results, remove the screw from the stud altogether and add another drywall screw a couple of inches above and below the screw pop, taking care not to penetrate the paper. Re-screw the original screw back into the centre of the screw pop, this will help reduce the amount of filling compound needed to fill the crater.

Step three: Fill the hole

Use your jointing or filling plaster and filling knife to patch up the hole. Apply the filler making sure that the hole is completely filled. Do this in two or three coats, leaving the filler to dry fully each time.

Step four: Sand

Sand the area using your sandpaper or sanding block. It is now ready for paint or wallpaper!


Part of the expertEasy team in Melbourne. Mark is a keen gardener, a DIY addict and a father of two beautiful girls. He is originally from Perth and is a true Eagles fan.

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