How to fix cracks in plaster
Easily learn how to fix cracks in plaster with our full guide. With step-by-step guides, top tips and information. Plus, how to tell if cracks are serious.
Most homeowners will have experienced cracks in their plaster walls or ceilings at least once and it can be hard not to panic. Seeing a long crack in the wall of your new home can be worrying, but how do you know if a wall crack is serious?
Read on to find out how to fix cracks in plaster, how to fix cracks in corners, fixing recurring cracks and what the best filler for cracks in plaster is.
How to fix cracks in plaster
Plaster is a handy material for creating smooth, strong walls that last for years and years. Unfortunately, over time, it’s also prone to cracks that look terrible and can sometimes be an indicator of a more serious issue. Learning how to fix cracks in plaster is a great skill to have that can come in very handy.
One of the best ways to fix cracks in plaster walls is to start by scoring the crack. This’ll help to remove any loose plaster and create a larger surface for the joint compound to adhere to. To begin with, you will need a range of tools and materials including:
- Stanley knife
- Filler knife
- Drywall tape
- Tray for mixing joint compound if necessary
- Drywall joint compound
- Vacuum cleaner
Top tip: Skip ahead to our ‘cracks in plaster, when to worry’ section if you’re concerned about your wall or ceiling crack before continuing.
How to fix cracks in plaster walls
Now you’ve gathered everything you’ll need, you can get started, but firstly, make sure you cover any surfaces and move any furniture out of the area to avoid damage from falling materials.
You may need to stand on a step ladder, especially if the crack is located on your ceiling. Then, use the following steps for quick results:
- Start by scoring the crack using your Stanley knife. Carefully remove any loose plaster and widen the crack.
- Vacuum the crack to get rid of any small pieces of plaster and dust.
- Next, cut a piece of drywall tape the length of the crack using scissors and set aside.
- Using your tray, mix the joint compound as directed by the packaging.
- Then, add a small amount of the mixture to your drywall knife and spread over the crack. Ensure you add a thin layer that covers either side of the crack.
- You can then take your piece of drywall tape and position it, covering the crack. Smooth out any bumps with your drywall knife but be careful not to rip the tape.
- Smooth another layer of joint compound over the crack with your drywall knife and allow to dry.
- Finally, sand the area until it’s flat and even but be careful not to sand down to the tape.
Top tip: This method also works well if you’re wondering how to fix hairline cracks in plaster walls.
How to fix cracks in corners of plaster walls
Sometimes cracks appear in difficult to reach areas like corners. Thankfully, it’s possible to learn how to fix cracks in corners of plaster walls. The best solution is to follow a similar method to that described in the previous section.
The main difference is that you apply more than one piece of drywall tape, covering each side of the crack. You can then lightly cover the tape with joint compound, let it set, then sand as usual.
How to fix recurring cracks in plaster
Frustratingly, even after you fix a crack in your ceiling or wall it can reappear over time. This is usually caused by a shift in your home’s foundations which is often nothing to worry about. Unsure how to fix recurring cracks in plaster? The best method to use is the one described in our ‘how to fix cracks in plaster walls’ section.
Alternatively, if your recurring cracks are more serious, it’s a wise decision to contact a professional. You can do this from the comfort of your own home, using our handy search engine for instant results.
How to fix cracks in plaster walls before painting
Not all cracks in plaster are the same and it may be useful to know how to handle these before they become an issue. Two different types of cracks are:
- Peeling plaster cracks: If plaster starts to peel away from your ceiling in large patches, it’s time to speak to an expert.
- Shrinkage cracks: These cracks branch out and spread over an area of your wall or ceiling. Minor shrinkage cracks can be repaired by filling them with plaster.
It’s essential that you fix any cracks in your plaster sooner rather than later to prevent the issue from worsening. That is why it’s so important to know how to fix cracks in plaster walls before painting. If you don’t address these problems prior to decorating, you won’t achieve a flawless, even finish and the cracks will simply reappear.
For most minor cracks the best method to use is that described in our ‘how to fix cracks in plaster walls’ section. Or, for more serious cracks, get in touch with a professional as soon as possible.
Treating damp mould on internal walls
Damp and mould can be incredibly insidious, spreading quickly up over your walls, floors and ceilings. They can even affect your furniture and possessions if they come into contact with them. As well as causing health issues, damp and mould look terrible. As such, treating damp and mould on internal walls is vital.
To guide you through the process of tackling damp and mould, our getting rid of black mould, condensation and damp article is a fantastic source of information.
What is the best filler for cracks in plaster?
Filling cracks in your ceilings and walls is important to keep your home looking great and prevent future issues. But what is the best filler for cracks in plaster? To pick the best option for you, you’ll need to do a little research.
For example, you need a filler that is hard-wearing and can be sanded down for excellent results. In addition, any filler that you pick should be fine and the same colour as your ceiling or walls.
How do you repair deep cracks in UK plaster walls?
When it comes to deep cracks, it’s difficult not to worry about any further implications regarding the structural integrity of your home. The truth is that it’s possible to repair these cracks yourself, although if they recur or are especially deep you may need to hire an expert to deal with them.
Wondering how to repair deep cracks in UK plaster walls? Use the below tips:
- Use a chisel or knife to carefully remove any debris or lumps of plaster from the deep crack.
- Fill with newspaper before applying plaster of Paris to add extra stability to the crack.
- Apply a layer of plaster over the newspaper covering the crack.
- Once that plaster is dry, add another layer and repeat until the wall or ceiling and the crack are level.
- Finally, use sandpaper to smooth over the area.
Top tip: If you’re worried your crack is serious or too large, skip ahead to our ‘cracks in plaster, when to worry’ section before attempting to fix it.
Cracks in plaster, when to worry
Cracks come in all shapes and sizes, some deep and some shallow but how do you know if a wall crack is serious? Generally, cracks in plaster are very common and usually nothing to be concerned about but there are instances when a crack could indicate a deeper issue. If you’re wondering when to worry about cracks in plaster, use the following guidelines:
- Width of crack: If your crack is wider than 0.5cm, it’s worth investigating. Once a crack reaches 2.5cm width this could mean your home has structural damage that needs to be quickly dealt with.
- Cracks over door frames: This could be a sign that your home’s foundations are damaged or moving so you should call an expert to assess the problem.
- Diagonal cracks: Any crack that runs diagonally or takes the shape of the bricks on the outside of your home needs to be looked at by a professional as your home’s foundations may be shifting.
Are cracks in plaster walls normal?
Absolutely, cracks in plaster walls are a normal part of owning a home and usually nothing to be concerned about. In fact, many new houses are prone to cracks while the house settles over time.
Of course, there are instances when cracks are more serious and the tips in our ‘cracks in plaster, when to worry’ section should help you to know whether or not to contact an expert.
Help, I’m worried about a large crack in my home
While it’s possible to deal with cracks yourself, sometimes a crack may indicate a structural issue in your home. If this is the case, then don’t delay hiring a professional to assess the situation. When it comes to hiring an expert you can trust, our members are fully vetted and highly qualified to deal with your problem quickly and efficiently.
It’s never worth trying to tackle a serious crack yourself as while you may temporarily hide the crack, the structural damage to your home won’t go away. Remember, it’s always worth hiring a tradesperson before the issue worsens and your home is badly damaged.
If you’re looking for further support, the HomeOwners Alliance website is an excellent source of guidance and information for any repairs, renovations or issues you’re having in your home.
How much does plaster cost to be repaired?
When you find cracks or holes in your plaster it’s normal to feel worried. However, we hope this guide has helped put your mind at ease and show you that most cracks are harmless. If you’d prefer to have a plasterer fill a small crack in your home, this will cost an average of £100.
To learn more, our drywall hole repair cost guide and our how to fill wall holes guide are both great sources of information and tips. If your plaster is in particularly poor condition, it may be time to fully replaster your room. The average cost to plaster a small room is £650 and our plaster room cost guide is a brilliant source of prices, considerations and more.
Which trade should you use for the job?
The best tradesperson for your job will depend on the extent of the crack. Small, minor cracks can be easily dealt with by a plasterer or general builder, but serious cracks need to be assessed by a structural engineer.