29th Mar 2022

Plaster Filler And Its Alternatives: What You Need To Know

Plaster filler can be an extremely handy product for a variety of DIY tasks, helping you to repair cracks and holes in plaster or plasterboard walls.

Polyfilla is perhaps the best known brand of plaster filler, but how exactly should you use it around your home, and what alternatives are available? From plaster filler to caulk and from powder filler to Swedish Putty, let’s take a look at the different types of filler and when to use them.

What Is Plaster Filler?

Plaster fillers such as Polyfilla are usually available in both ready mixed and powder forms, and can be used for a variety of DIY tasks, including:

  • Filling holes caused by nails or screws
  • Filling in cracks in walls
  • Smoothing knocks caused by hammers
  • Covering up cracked paint

If you’re ever concerned about the size of a crack in one of your walls, call in a professional to check it over for peace of mind. 

Polyfilla provides a smooth surface that can be plastered over, or decorated over with paint or wallpaper, and you can even drill nails into it, making it a sturdy, long-term solution. Plaster filler is a better option than plaster for filling in cracks, as it can be easier to control, apply, and smooth out when you’re working in a small area.

When it comes to buying plaster filler, always check the details of the specific product; some plaster fillers are water-resistant or have a heat-resistant formula. If you’re filling in gaps in your bathroom or kitchen, always make sure you’re using the most appropriate type of filler. And if you’re looking for an external plaster filler, make sure you’re buying a specialist product for the task at hand - ask for advice from a professional if you’re unsure what to use. 

4 Plaster Filler Alternatives And When To Use Them

Although there are lots of different types of Polyfilla out there, it’s only one of the many types of filler on the market. Here are four different kinds of plaster filler and when to use them:

1. Caulk

Caulk is a type of waterproof filler that can be used as a sealant - it’s often used in kitchens and bathrooms. Caulk can help to seal joints and seams around pipes or tiles to prevent both air and water leaks.

Typically made from a blend of latex and other acrylic materials, caulk is a little different to other types of sealant, as it’s not quite as elastic, but it can still be a great choice for large-scale DIY projects. 

Caulk can be used along skirting boards and to seal corners and joints, but bear in mind that it can be prone to cracking, so make sure you follow the manufacturer’s instructions to the letter. 
 

Depending on the size of the job, you won’t necessarily need any specialist caulking tools, as you should be able to apply the product with a finger or even a spoon, as you’ll most likely be working in a small area. Always wear protective gloves when handling any DIY product by hand.

What’s The Difference Between Plaster Filler And Caulk?

Although caulk is technically a type of filler, as it fills in gaps, it cannot be used in the same way as a plaster filler for filling in gaps in walls. This is because caulk cannot be sanded down and painted over.

2. Powder Filler

Powder fillers provide an alternative to ready mixed plaster fillers, but it’s important to bear in mind that they can shrink when applied to deep cracks. This means you may need to apply more powder filler over time than you would other types of filler, potentially making the job more expensive. 

Powder fillers are typically mixed with water to form a paste that can be used to fill holes, but you may want to mix the filler with emulsion for a harder finish. This type of filler should take just a couple of hours to dry, so you can quickly move on to sanding, painting, or drilling.

3. Swedish Putty

Swedish Putty is another brand of plaster filler, this time from Fine Paints of Europe. Swedish Putty is described as an ultra-fine filler, and it’s suitable for sanding. This DIY product is often used by decorators to smooth gaps or cracks in walls before they are painted over. 

You can apply Swedish Putty to walls using a clean knife; for curved surfaces, use a gloved hand, or a sponge to apply the filler. Leave to dry for 12-24 hours before sanding down for a smooth finish ready for decorating.

4. Wood Fillers

If you’re filling in gaps or cracks in a fence, wooden beams, or another type of wooden support, use a specialist wood filler rather than a plaster filler, as it will be specially designed for the task at hand. Wood filler is also sometimes referred to as wood putty or grain filler, so look out for these terms when you’re shopping for wood filler.

You can get ready mixed wood fillers, as well as what’s known as two-part fillers, which typically contain a chemical hardener too. Sometimes, wood fillers are made from wood combined with a binder, which helps to recreate the colour of a specific type of wood in the gap you’re trying to fill.

What Is The Best Filler For Plaster Cracks?

There’s no one-size-fits-all answer to ‘what’s the best type of filler?’ as it depends on the specific task at hand, the size of the gap you’re trying to fill, and how you plan to decorate the space afterwards.

However, a plaster filler like Polyfilla or a powder filler are probably the best options for filling plaster cracks, as alternatives such as caulk are best used for other purposes, like sealing gaps around pipes or tiles.

How To Fill Plaster Cracks

Here’s how to fill plaster cracks in your walls:

  • Score the crack open using a utility knife to make sure there are no sharp edges, or pieces that are about to crumble before you fill in the gap ready for decorating
  • Wearing protective gloves, and using a sponge or palette knife, apply your chosen plaster filler to the wall
  • Leave to dry thoroughly - you may need to leave the wall for 24 hours or more
  • Use sandpaper to sand the filled gap until you have a smooth finish - you may need to repeat this step several times
  • The wall should then be ready to paint or paper over

DIY Tools At U Value

You’ll find a variety of different fillers available at U Value, including Knauf Joint Filler, Gyproc Fillers-Easi-Fill, and Gyproc Fillers-Premium Fill in our extensive range of DIY accessories, which also includes everything from primers to screws and from basecoats to joint adhesives. Explore our full range of DIY accessories here.

If you’re unsure which type of filler is right for your project, please don’t hesitate to get in touch with any questions.