Best wood fillers guide UK – Reviewed by professionals

9 Aug

Best wood fillers guide UK – Reviewed by professionals

We would know that good-quality wood fillers are hard to come by. Chameleon offers wooden window restoration services, so we need the highest quality wood filler possible.

Whether we are treating rot or filling in an old nail or screw holes in exterior woodwork, the wood filler we use needs to be the absolute best in order for our work to stand up to the elements over time. During our many years of offering sash window restoration services, we’ve used a range of wood fillers and have narrowed down our search for the best fillers to use, and we’re here to tell you all about them. First, though, let’s look at the types of fillers available. 

Types of Wood Fillers

There is a range of wood fillers available on the market. Some are great for all interior woodwork, while others work well for interior and exterior wood. Choosing the right wood filler is key to a project’s success. Choosing the wrong wood or wall filler for the job can shrink and crack over time. 

Vinyl Wood Filler

vinyl wood filler

Vinyl wood filler is one of the most commonly used fillers on the market. It typically comes pre-mixed and comes in loads of colour variations to match the wood or blend in nicely under the paint. As these are pre-mixed, they often have a long drying time but do offer a good finish if you can match the filler to the wood. 

Epoxy Wood Fillers

Epoxy fillers come in two parts; the filler itself and then a catalyst. Once you add the catalyst to the filler, you have a short working time, and then the filler will set extremely quickly.

Again, these fillers come in various colours to match wood and can be stained with wood stain prior to adding the catalyst. Epoxy fillers are fantastic for filling voids as they don’t shrink over time, and they are as flexible as wood.

Once dried, they can be sanded for a smooth finish, painted, and even look great underwood oils and varnishes too. For us, Epoxy wood fillers are the most versatile filler on the market. 

epoxy wood filler used for window repair

Gypsum–Based Wood Filler

Gypsum is the same material used in many wall plasters. As a result, gypsum-based fillers can be excellent when you need a breathable filler. It isn’t as flexible as some other fillers, though. So, if a room sees a lot of temperature changes throughout the year and the wood moves a lot as a result, an epoxy filler may be better for you. Still, gypsum-based fillers can be used to fill cracks, holes and more in a lot of different materials.

Cellulose–Based Wood Filler

cellulose–based wood fillers

Cellulose filters are incredibly strong because they have real wood fibres in them. It is basically like filling a crack in wood with MDF. They usually come as a dry paste that you mix. The binders in this filler dry it very quickly, so while you don’t get much working time, you can sand it, drill it and paint it very quickly after applying. 

Latex Wood Filler

Latex filler is a water-based wood filler that doesn’t crack or shrink over time but can during the first few hours of application. After the water in the filler has evaporated, the filler can shrink and crack, which means you’ll have to add more. If you are prepared for this, latex is a good option. It is really flexible and can be dyed, painted, sanded, drilled and more. 

3 Best Wood Fillers Of 2023

Now you know a bit about wood fillers, here are our top picks for the best wood fillers in the UK in 2023. 

Repair Care Dry Flex Resin-based Wood Filler

Dry Flex is our go-to filler. It can be used for all repairs, refurbishments and decorating tasks in wood. It is highly flexible, which makes it ideal for exterior applications that will move throughout the seasons. However, it is also highly durable and resilient. This means it can be sanded, drilled, cut and more. 

We use this wood filler for a host of tasks. We fill in small areas of rot with this filler, and it strengthens the wood around it. We also use it to fill in old nail holes and a great deal more too. It is a two-part epoxy resin filler that can be stained after application, and it works brilliantly under the paint. 

dryflex wood filler

Everbuild Two-part High-Performance Epoxy Wood Filler

If you need a wood filler that is very, very tough and matches the colour of wood perfectly, this is a solid choice. This wood filler from Everbuild comes in a host of different colours to match a lot of common woods around the home, including oak, pine, mahogany and redwood.

This filler can also be stained to match the colour of any seasoned or raw wood and takes varnish very well. After just 30 minutes, you have a filler that can be sanded, drilled or varnished to create a nearly invisible wood repair. It is suitable for all temperatures within the UK and hard-wearing enough to be used on flooring and just about anywhere else in the home. 

Rustins Professional Wood Filler

Rustins make some of the best and most high-quality wood stains, varnishes and fillers on the market. So, it’s no surprise its fantastic wood filler ended up on our list. This is also a two-part epoxy filler that dries in just 30 minutes. It is ideal for indoor and outdoor projects and comes in a natural colour that can be stained, varnished and a great deal more. 

This is an ideal filler to use if you have different materials to repair. This can be used on wood, metal and concrete to repair many different cracks, voids and holes with a single tub of this filler. This filler is available in 1-kilo tubs, which sounds excessive for smaller projects. However, because it can be used on loads of different materials and has a very long shelf-life, you will use all of it.

Best wood filler for windows repair task

Repair Care International Dry Flex Wood Filler

For our money, the best wood filler on the market, without question, is Dry Flex from Repair Care International. It is the most hard-wearing epoxy filler we have ever used, and it is so easy to apply. a 400ml pack of this filler also goes a very long way. It spreads really thinly compared to other fillers, so you really don’t waste much of it during a project. 

We realise Dry Flex is much more expensive than the other fillers on this list, but it is well worth the money. It is the most robust filler on the market and so easy to work with. Whether you need a filler for exterior or interior woodwork, this is the one we’d choose.

Our Pick
Repair Care International Dry Flex Wood Filler

Repair Care International Dry Flex Wood Filler

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What to Look for in Wood Filler

what to look for in wood filler

Choosing a wood filler isn’t as easy as walking into any shop and grabbing the first one you see. There are a lot of wood fillers available that are more trouble than they’re worth. So, here are some things to look for in wood filler that will help you get your project done right the first time. 


Can the filler you intend to use be used on every material you need to repair? Can it take all of the finishes you need it to? Is it only for the interior, or is it an exterior wood filler too?

Drying Time

drying time of wood filler

Some wood fillers can dry in 30 minutes and be painted right away; others take 24 hours to be ready to be sanded. Choose a drying time that suits your schedule. 

Task: Indoor Vs Outdoor Use

It is always worth buying a wood filler that can be used for both interior and exterior wood. You may only need interior wood fixing right now, but what about in three months? Most wood fillers have a long shelf life, so you might as well use them!

tasks for wood fillers


If you are buying a pre-mixed filler, don’t buy a massive amount unless you have a massive amount of filling to do. These dry out quite soon after you open them. If you are using a two-part epoxy filler, though, these have a much longer shelf life, so you can buy more than you need right now without wasting them. 

Wood Putty Vs Wood Filler

wood putty vs wood filler

Wood putty is a solvent-based product that remains pliable after you have applied it. It is much denser than filler, so you need a putty knife to apply it.

Putty doesn’t shrink or crack because it is oil and plastic-based. However, because it remains so flexible after use, it cannot be sanded like wood filler.

Many wood fillers replicate the flexibility of putty but can also be sanded, so for most tasks, wood filler is the best option. So the only real difference between wood putty and wood filler is that putty can’t be sanded, drilled or cut once applied. 


We hope this look at wood fillers has helped you decide which one is right for your next project. As we said, we love the versatility and robustness of Dry Flex.

However, if you can’t justify the price of this filler, any two-part epoxy filler we mentioned above will be a solid choice. Why not explore Chameleon’s blog more for other helpful tips and products for DIY and woodworking projects? 


Can you paint the wood filler?

Yes, most wood fillers can be painted once dry. 

Which is Better, Wood Filler or Wood Putty?

For most DIY and woodworking projects, wood filler is the better option if you intend to sand, drill, paint or apply varnish to it.

What wood filler do professionals use?

We use two-part epoxy wood fillers like Dry flex. In our experience, two-part epoxy fillers work extremely well on all exterior and interior woodwork. They are quick to apply, don’t shrink and provide endless possibilities when it comes to staining and painting.

Is wood filler as strong as wood? 

In many cases, wood filler is often stronger than the wood itself.

Can you fill large holes with wood filler?

You can, but depending on the filler you use, you’ll likely have to fill deep holes in stages. All wood fillers state how thick they can be applied in the instructions. 


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