Exterior wood fillers are an important part of many home maintenance projects. They can help protect your home from the elements and keep it looking its best by repairing cracks. You may also use them to prepare a surface before painting, or fill holes in your wooden decking, for example.
But with so many different types of exterior wood fillers on the market, it can be hard to know which one is right for you. This blog post will compare some of the most popular exterior wood filler brands and help you decide which one is best for your needs. You’ll find some answers to the most common questions you are likely to have about exterior wood fillers too.
Considerations When Buying Exterior Wood Filler?
When choosing an exterior wood filler, there are several things you must consider. Certain products are suited for certain types of repair, and conditions, so you should consider each job individually instead of sticking with the same filler all of the time. These are some of the main considerations when buying exterior wood filler.
The Size and the Type of Repair
The first thing you should do is determine the size of the hole or crack you are trying to fill. If your repair is small, basic fillers will suffice. However, large cracks and holes are harder to fill properly and may require multiple layers of specialist filler.
Epoxy wood fillers are a two-part product that has to be mixed before application. This is the strongest of all of the types of wood filler and it will hold cracks together and prevent them from widening. In many cases, this is your best option as the repair will last a long time, as long as the filler is applied correctly.
People often use the terms ‘filler’ and ‘putty’ interchangeably but they are not the same thing. Putty is more flexible and suited to fixing small holes, like nail holes, or very think cracks. Filler, on the other hand, has a harder finish and can be sanded after it has dried. It is important that you use an exterior filler, not a putty for fixing large holes and cracks.
Make Sure it’s Exterior Graded Filler
Make sure that the filler you want to purchase is exterior rated. This means it can be used outside without disintegrating, cracking, or rotting. The filler must be resistant to water and dust or it will not stand up to the elements.
Always check the tin and if it doesn’t specify that it is safe for exterior use, consider a different product.
Is it Stainable and/or Paintable?
How will you finish the surface of the filler once the repair is finished? You want it to blend in with the rest of the surface so you cannot see the filled area, so you must ensure it can be painted or stained. Look at the surrounding material and make sure that the filler can be coated in the same finish (paint or stain).
Most wood fillers are not porous like wood, so they require extra preparation for the paint or stain to bond properly to the surface. Take the following steps:
- Sand the filler and the surrounding area to rough it up.
- Apply a primer over the filler and the surrounding area. This creates a completely smooth finish, so the filler will not be noticeable under the paint.
- Apply paint according to the instructions on the tin.
The Dry Time
You should always check the dry time on exterior filler so you can plan the repair accordingly. How long will you have to wait before you can paint over it? Will it dry before it rains again? It is important that the filler is fully dried and ideally painted over before it is exposed to excess moisture, or the finish could be ruined.
Will it Crack or Shrink Over Time?
Consider whether the filler is likely to crack or shrink over time and how this will impact the repair. In most cases, this should not be a problem, but only if you prepare the area properly before application.
Make sure that you remove any rotten wood and other debris and dust as this will stop the filler from bonding securely to the surface. Clean the area too, so you can get the best possible finish. This will reduce the chances of cracking and shrinking in the future.
What You Put Over the Filler Is Most Important!
As we said before, most exterior wood fillers can be painted or stained to suit your needs and match the surrounding area. The best way to cover it is by using exterior wood paint. This will cover up the filler and blend it into the surface of the wall or fence. But it also has the added function of protecting and sealing the filler, just as you would with the rest of the wood. You use paint or stain to protect wood against the elements and make it last longer, and the same is true of the filler. Although it is designed to withstand the elements, it will last much longer when properly protected.
10 Best Exterior Wood Fillers
Bondo Home Solutions Wood Filler is the most durable exterior filler on the market right now. It is a 2-part epoxy filler product that gives a very strong, long-lasting repair that won’t shrink or crack over time. This makes it ideal for large cracks and holes. This filler can be used on doors, fences, windows, etc.
It is designed for both exterior and interior use and is plenty durable enough for outside use as it is fully water-resistant. Once applied, it only takes 15 minutes until it is dry.
When applied, it has a brown color that blends fairly well with most woods. However, it is easy to paint and it takes paint and stain very well. It should be ready to paint or stain roughly 25 minutes after application.
If you have exterior features that are rotting and you want to bring them back to life, the Abatron WoodEpox Wood Replacement Compound is perfect. This is a heavy-duty 2-part epoxy filler that can replace large sections of decaying wood and maintain structural integrity. It can easily be sanded, painted, and worked in the same way that wood can, so it’s ideal for repairing exterior features.
The no-slump finish means that it holds firm and can fill large holes, but it also allows you to use it for decorative restorations. By molding the filler to imitate the shape of decorative features, you can get an unrecognizable finish once it is painted.
This filler is also GreenGuard Certified because it contains almost no VOCs (volatile organic compounds). Some other wood filler products contain quite harsh chemicals that give off fumes and potentially cause environmental damage.
When making smaller repairs, the KwikWood Wood Repair Epoxy Putty Stick is ideal. It works brilliantly for wooden window and door frame repairs and fixing small areas of rot. It’s a simple 2-part epoxy filler that is quick to mix and apply, and it can be machined or sanded after just an hour. It will dry a light tan color but is easily stained or painted once dry.
It will not shrink or crack as long as it is applied properly, so it’s perfect for aesthetic repairs on exterior wooden features. However, it is not suitable for any large structural repairs. It is also completely solvent-free, so no need to worry about fumes in tight spaces.
When repairing large areas of rotten wood, the PC-Woody Wood Repair Epoxy Paste is the right filler for the job. The high tack formula means that it does not sag or drip while it is drying as some other fillers can. So, if you are doing overhead work or fixing intricate features, you can rely on this filler to hold its shape until it is fully dry.
It is a 2-part epoxy filler that needs to be mixed prior to application. It will dry in roughly 40 minutes in average temperatures, after which it can be painted and stained, or machined. It is also highly resistant to the elements, as well as rot and chemicals that may already be present in the wood, making it perfect for those big exterior repairs.
This DAP Plastic Wood Filler is a solvent-based filler that creates an incredibly tough finish. Once fully dry, the filler is 3 times harder than the original wood, so it’s the right choice for those situations where strength and durability are your priority.
The filler actually contains real wood fibers, so it behaves just like real wood when you sand, machine, and paint it. The increased strength provides a good anchor for screws and nails without the risk of splitting, so it’s a good product to use if you need to attach anything to the surface after repairing it.
It comes in a variety of wood shades, but can also be stained and painted easily.
If you want a filler that is very easy to apply and gives a great finish without too much work, the FamoWood Latex Wood Filler is ideal. It is a latex-based product, so it does not require mixing like epoxy fillers. It spreads very smoothly and fills cracks beautifully, giving a very even finish. Although some sanding is required, it will already be relatively smooth. So, if you are not that experienced with using wood filler and you have cracks to repair, this is an excellent product.
The filler contains high amounts of wood flour (wood chips that have been dried and ground to fine dust), which allows it to take stains and paint just like real wood does. It’s a fast-drying filler that should be dry to the touch in 30 minutes, so it’s ideal for quick fixes that look great.
Donald Durhams Rockhard Water Putty is a gypsum-based filler that comes in powder form and must be mixed with water. It is quick and easy to mix and apply, and it’s great for practical jobs like filling nail holes or small cracks. However, if aesthetics are important, it may not be the best product. It does not take stain particularly well, and you will need quite a few coats before you get an even finish. If you want to color the filler, it is better to do this during the mixing stage using oil-based coloring.
Overall, it’s a very reliable filler for patching things up and it does give you a durable finish that won’t crack or shrink. But if you want to hide repairs for aesthetic reasons, consider a different filler.
This Minwax Stainable Wood Filler has been designed with painting and staining in mind. It works best when repairing small cracks and damage like nail holes or knots in wood. But it can be used for larger repairs if you apply multiple layers, giving enough time for it to dry between each layer.
Once it has dried, it can be stained with both oil-based and water-based products. The finish looks very realistic, and you can even score thin lines in the filler before you stain it to imitate the grain of the wood. It is specifically designed for use with Minwax penetrating wood stain and the Minwax clear protective finish. This combination of products gives excellent results. However, you can still use it with other brands of wood stain and get a great finish.
Painters putty is a great multi-purpose filler that can be used on all kinds of hard substrates, including wood. Crawford’s Natural Blend Painters Putty is one of the most popular brands on the market, and for good reason. It’s a very malleable putty that is simple to apply to cracks and nail holes, giving a completely seamless finish. Once the repair has been painted, it will be invisible once it has been painted.
However, be aware that this painter’s putty takes a lot longer to dry than other filers on this list. It can be up to 24 hours before a skin forms and 2 or 3 days before it is fully dry and ready to work. It is worth waiting as the finish is excellent, but you need to accommodate for the drying time when planning projects.
If you need a heavy-duty wood filler, Elmer’s Probond Wood Filler is an excellent professional strength product. This filler is designed for use by construction professionals but there is no reason why you can’t use it for residential products.
The finish is much harder than most commercial filler products and it can even stand up to a high-speed electric sander without any risk of cracking. It also holds screws and nails brilliantly.
It comes in a range of colors but it’s also great for staining because it contains high amounts of wood fibers. For those jobs where you can’t always avoid being a bit heavy-handed with the repair, this is a great product. For example, if you wanted to fix large cracks in your decking before sanding the whole thing, this filler would work brilliantly.
What’s the Best Exterior Wood Filler for Large Holes?
The PC Products PC-Woody Wood Repair Epoxy Paste is the best filler for large holes. When filling a large hole, sagging and drips can be a big problem. It is important that the filler can hold its shape without sinking until it is fully dried. Other products that are designed for smaller repairs cannot do this, but the PC-Woody Wood Repair Epoxy Paste has a high tack formula that holds its form brilliantly.
Epoxy fillers tend to be better for large holes too because they are easy to handle and apply to the hold. They don’t shrink very much either, which is crucial if the repair is going to stick. For these reasons, the PC-Woody Wood Repair Epoxy Paste is the best choice for large holes.
What’s the Best Exterior Wood Filler for Decks?
When repairing damage to your deck, there are two key things you should consider; durability and aesthetics. The filler needs to be hard-wearing enough to stand up to sanding, as well as all of the foot traffic on your deck. You also need to be able to blend it well with the color so the repair is not noticeable.
Elmer’s Probond Wood Filler is the best option because it meets both of those needs well. After you have repaired the deck, you may want to sand it back and refinish it. This incredibly durable filler will stand up to industrial-grade electric sanders without cracking. It also has a lot of natural wood fibers in it, so it takes stain very well, making it easier to hide the repair and make your deck look flawless.
When Should You Just Replace the Wood?
Even though fillers can repair a lot of extensive damage to exterior wood, there comes a point when you should just replace it instead of trying to fix it. This is when the damage has gone so deep that repairing it would be very difficult or potentially dangerous.
Consider how well rotten wood is holding together. You may be able to stick filler into the holes but that doesn’t mean it will stay there. If you can easily pry the wood away from the main structure without too much force, it needs to be replaced. But if the structural integrity is still there and it is only small surface areas that have rotted, it can be repaired. Start by removing all of the rot to determine how much healthy wood remains underneath. This will help you decide whether the structure is still sound or not and whether the wood should be replaced.
In the case of termite damage, your chances of a repair are much slimmer. If you catch the infestation early before they have caused too much damage, you can remove some of the ruined wood and fill the gaps. But if they have already eaten deep into the wood, it should be replaced entirely.
What to do if You Never Used Wood Filler Before?
If you have never used wood filler before, follow these basic steps when making repairs:
1. Clean the area to remove any loose pieces of wood, nails, or other debris that might contaminate the filler and make a mess.
2. Fill the damage with a thin, even layer of filler that is blended into the surrounding wood as smoothly as possible.
3. Allow it to dry completely before sanding or staining.
4. If needed, reapply a second coat and let it dry again before using your chosen coating.
Preparing the area properly is crucial, and it is always important to follow the application and safety guidelines on the back of the product. All wood fillers are slightly different, so never apply filler without first reading the directions.
It is also a good idea to test the filler on a piece of scrap wood. This ensures that you have mixed it properly (if necessary) and the finish is good.
Exterior Wood Filler FAQs
What is Wood Hardener? When Should I Use it?
Wood hardener strengthens the wood without adding a layer of filler. It can be applied to rotted or damaged wood to create a better surface for applying filler on top. Wood hardener can also be used to stop decay, so if you notice that wooden fixtures are starting to soften and rot, apply a hardener right away before repairing the damage.
Can I Use Exterior Grade Caulking Instead?
Yes, you can use exterior grade caulking, but only in certain cases. Caulk is good for filling small gaps and cracks, especially around wooden window frames and doors, but it is not suitable for large repairs. Regularly filling gaps with exterior grade caulking can help keep your home warm and prevent drafts.
When using caulk, it is important that you pick the right product. Some are better suited to painted wood while others are designed for specific types of wood. Always check the manufacturer’s guidelines to find a product that is best suited to the wood you are repairing.
What’s the Difference Between Interior and Exterior Wood Filler?
There are a few differences between interior and exterior wood filler. Exterior fillers typically dry much harder than their interior counterparts, making them suitable for harsher weather conditions. The exterior fillers also cure much faster because the drying process is sped up by being outside.
Although both types of filler will repair damage to wood, you should always use a dedicated exterior filler when working outside. Interior fillers will not be durable enough and the repair will not stick.
What are the Different Types of Wood Fillers?
There are several types of wood filler to choose from; Epoxy-based, water-based, latex, gypsum-based, and cellulose-based.
Epoxy-based fillers tend to be the best at filling large gaps and cracks in wood. They both dry hard and are resistant to moisture, making them suitable for exterior use. Latex fillers are best suited to lighter, thinner repairs because they give a smooth finish. But they don’t hold their shape well enough to fill large holes.
Gypsum-based fillers dry hard and smooth and they are good at taking paint. However, if you are planning to use wood stain, consider using epoxy fillers that contain wood fibers or flour.
Cellulose-based fillers give great adhesion and don’t shrink, making them great for use on a variety of different wooden surfaces.
Exterior wood filler is an integral part of any do-it-yourself home repair project. Using the right filler for your specific needs will ensure a professional finish.
Not all wood fillers are created equally, so always read the manufacturer’s guidelines before you start your repair. Just make sure that you always use an exterior-grade product.
Always test out a small amount of filler on a piece of scrap wood first to ensure that it creates the desired finish before you start any big repairs.
Jamie is the founder of The Backyard Pros. When he was 15 years old he started working at a garden centre helping people buy plants, gardening products, and lawn care products. He has real estate experience and he is a home owner. Jamie loves backyard projects, refinishing furniture, and enjoys sharing his knowledge online.