How to repair plaster walls 101

Repairing your plaster walls or ceilings yourself can be a great way of carrying out a relatively straightforward DIY task while at the same time saving money. Due to time and the general wear and tear of modern life, things around the home can often break or become damaged, and the same goes for walls and ceilings. Knowing how to repair plaster walls can be a great bit of knowledge to have, and with our straightforward Step-by-Step How To you’ll soon be fixing up cracks and holes with ease.

 

How to repair plaster walls if they’re damaged

Finding loose plaster or cracks in your walls can be a bit of an unsightly nuisance as well as a worry, but with the right know-how, you can quickly get to work repairing any damage you may find around your home.

Tools and materials

The first step, which goes for all DIY jobs around the home, is to make sure you have the correct tools and materials to hand. For repairing damaged plaster you will need the following:

  • Trowel
  • Chisel
  • Hand brush
  • Sandpaper block
  • Plaster mix
  • Clean water
  • Joint compound
  • Two buckets
  • Protective clothing
  • Dust sheets

1) Preparation

Next, you will need to prepare the area for the upcoming work. Lay down your dust sheets and remove any loose plaster with the chisel. Don’t forget your protective clothing, including a dust mask, as your work area will quickly begin filling with dust.

2) Mixing plaster

Once your wall is free from any crumbling plaster or other debris, mix up the required plaster for your wall repair. To create your plaster, simply combine together the clean water and plaster mix within the bucket, making sure to add the correct amount of mix according to the manufactures instructions. Stir the water and plaster together until your mix is of a creamy consistency with no lumps.

3) Applying the plaster

Using the trowel, start applying the plaster mix over the damaged area. As the first coat begins to set, cross scratch the mix as this will help the next coat to stick to the surface easier.

After waiting roughly an hour for the first coat to dry, apply the second layer, again making sure to cross scratch as it begins to set.

4) Applying the joint compound

Once the second layer of plaster has dried, you will want to apply a joint compound over the top. Start by mixing the compound in the second, clean bucket while carefully following the packaging instructions. Next, begin gently applying a thin layer over the once damaged area.

Allow the joint compound to dry before using a sandpaper block to sand the area down and then you’re done. All that’s left now is to enjoy your new, damage-free plaster wall.

This is what a damaged wall looks like - how to repair plaster walls

How to patch plaster wall holes

Cracks or loose plaster on walls can easily be resolved simply by following our straightforward instructions set out above in our How to repair damaged plaster walls guide, but when it comes to actual holes in your plaster wall, you’re going to need to follow a slightly different method.

1) Tools and materials

First, gather your tools and materials, of which you will need the following:

  • Small trowel or spatula
  • Chisel
  • Sandpaper block or sandpaper
  • Utility knife
  • Bucket
  • Protective clothing
  • Dust sheets
  • Fibreglass mesh
  • Cloth
  • Plaster mix
  • Clean water

2) Preparation

After laying down dust sheets around the work area, you will want to start to get to work on cleaning the hole in your wall. Begin by brushing away any loose plaster around the damaged area as well as any dust there may be left afterwards.

3) Adding the fibreglass mesh

Measure up your hole before covering with the fibreglass mesh, making sure you cover the hole by a good 20-30mm on all sides.

Once your fibreglass mesh has been firmly placed, it’s time to get to work on covering the hole with filler. Use a small trowel or spatula to gently push the filler through the mesh until the area is completely covered. Remove any excess filler so that your new surface is nice and smooth, and allow to dry for roughly an hour.

4) Sand down the area

Using either a sandpaper or a sandpaper block, gently rub down the area before applying another layer of the filler. Again, allow to dry before sanding down.

Give the area roughly a day to completely dry and settle, and remove any excess dirt or dust, and your unattractive hole is now a thing of the past.

 

Filling large holes in walls

Filling in cracks and smaller holes in plaster walls is often a fairly straightforward job, as highlighted above, but repairing larger holes can be altogether a slightly trickier undertaking.

1) Tools and materials

First gather the correct tools and materials; you’re going to need the following:

  • Trowel
  • Chisel
  • Hand brush
  • Utility knife
  • Sandpaper block
  • Plasterboard off-cut
  • Filler
  • String
  • Bucket
  • Protective clothing
  • Dust sheets

2) Preparation

Start by clearing away any loose plaster or dust from the damaged area as well as making sure to neaten the hole’s edges. Find a piece of plasterboard off-cut larger than that of the damaged area yet capable of still fitting through the hole.

3) Preparing the plasterboard off-cut

The next step to covering the hole can be slightly tricky, but with patience and the right know-how shouldn’t be too much of an issue. First, drill a hole through the plasterboard off-cut then push through a string of thread. Now tie a nail to the end of the thread and apply the plaster repair around the edge of the front of the plasterboard off-cut.

4) Covering the hole

Push the plasterboard off-cut through the hole while at the same time remembering to keep a hold of the string. Then, pull the string back through the hole to move the plasterboard off-cut into place. Apply more of the plaster repair over the off-cut to ensure the hole is now firmly covered.

5) Finishing the job

Once the hole is entirely covered you will want to leave the area to dry. Tie a pencil or other weight to the end of your string to hold the plasterboard off-cut in place throughout the drying process. Leave until the plaster is completely dry before cutting away the loose string and going over any unfinished areas. Again, leave to dry before sanding down the surface.

how to repair plaster walls

How to repair blown plaster

Discovering you’ve got blown plaster, otherwise known as damp, can be a frustrating problem, and if not dealt with correctly can lead to further issues within your home.

When dealing with blown plaster the first step is usually to find the source of the damp, as resolving this will help prevent the issue from reoccurring in the future.

1) Remove the mould

Once the source of the damp has been resolved, you will need to allow the area to completely dry out before starting any repair work. Once dry, treat the wall with a mould removing treatment while making sure to carefully follow the packaging instructions.

2) Protect the area

After cleaning the area of all mould and allowing the surface to dry out, you will want to paint over with a damp seal or stain blocker paint as this will help prevent any staining of the emulsion when applied.

3) Repaint

Again, allow the area to dry before painting over the once damaged area with the wall’s original paint colour.

 

In summary

Whether you plan on patching up the odd crack or attempting to fix up a large scale hole, knowing the basics of repairing plaster walls can be a great help in getting them back to their best. However, when it comes to the actual hard work itself, sometimes hiring a quality professional is the better option. So if you’re after a qualified plasterer, of other tradesman, contact us here at HOMYZE. Our tradesmen are all fully vetted and can be booked online, through the app, or simply by phone.