What Size Nails for Baseboard Trim

Baseboards are one of the finishing touches that helps a wall look complete. Even the plainest baseboards can help protect drywall and create a more finished look. Nicer versions can add to the appearance of a whole room if they’re applied well.

The problem is that baseboards can be a lot trickier to attach than they seem at first glance. Slight irregularities in the wall and the baseboard material itself add complications. Not to mention that baseboard trim can be delicate and prone to breakage. Poorly attached baseboards are likely to fall off or get damaged, making a secure attachment even more important.

The most common tool used to attach baseboards are nail guns, thanks to their speed, precision, ease of use, and versatile sizes and styles.

Even if you have a great nail gun, you still need to choose the right nails for your baseboard trim. We’ll dive into everything you need to know to choose the right nails for your baseboard project, and what factors you should consider for different projects.


What Do You Need To Consider Choosing Nails for Baseboard Trim?

Every home is different, and every baseboard is a little different. Before you can choose the right nails for your project, you need to think a little about the baseboard itself and what kinds of nails it will best tolerate.

Here are the key factors you need to consider when you’re choosing what size nails you need for baseboard trim.


One of the primary things you should consider when you’re choosing what size nails for baseboard trim is the security of the trim itself. Ideally, you should have at least 1 nail fastening the baseboard into every stud in the wall. Some more complicated trims, or more challenging wall shapes, may need additional fastening.

The thicker and more complicated your baseboard trim, the more secure it needs to be to the wall. A loose 3-layer baseboard is more likely to cause problems than a loose 1-layer baseboard. Longer and thicker nails offer better fastening power, which means that they are the more secure option.

However, you need to balance security with the appearance of the nail. We’ll talk more about nail visibility in the next couple of sections.

Common Baseboard Stress

Just like any other building materials, baseboards experience a range of stresses that affect how you work with the material. For instance, hardwood baseboards with flex and expand more if you’re installing them in a humid area with large temperature swings. More expansion means that you’ll likely need longer nails, and more nails, to safely attach baseboards in that area.

Baseboard that’s placed in high-traffic areas of the home will also need more security from longer nails and thicker nails, compared with baseboard in low-traffic areas.

Think about where you’re placing the baseboard and the common types of stress that will affect your baseboard’s material when you’re choosing the nails. You’d be amazed how often common baseboard stress will change what size and length of nail you want to use.

Materials and Thickness

The materials and thickness of the baseboard itself also impact the size and length of nails you’ll need to apply the trim. Thicker baseboards need longer nails. Up to about 3.5 inches long is the average, but very ornate and multi-layered baseboards might need nails that are even longer.

You should also consider the kind of material you’re working with. Baseboards that are made from solid lumber that’s been milled into shape may be more durable than a baseboard made with veneers. Plastic baseboards might be more prone to splitting than pine or cedar, but some kinds of hardwood might be more finicky than plastic.

The more delicate and finicky the material, the more likely you’ll need thinner nails. Think about using brad nails, and more of them, for delicate baseboards. Sturdier materials might be better served by thicker 16-gauge nails, and you can sometimes use fewer of them to help keep the nails less noticeable.

Nail Visibility

In terms of nail visibility, smaller is always better. The smaller and thinner the nail and nailhead, the less noticeable it will be in your baseboards. Lower visibility provides a more professional-looking finish. Smaller nails can also be easier to fill in if you want to completely hide the nail marks. That means less work for you, and less time spent installing the baseboards.

However, the smallest nails aren’t always a good option, especially in high-traffic or high-stress areas. Nail visibility might be important for the finish on your baseboards, but the security and stability of your baseboards are much more important.

Size and Ease Of Access

This consideration usually won’t make a huge difference in which nail size you choose, but it’s worth thinking about. Larger nails usually mean larger nail guns, which can be difficult to maneuver into corners and other difficult spaces. Occasionally, you might want to choose a smaller nail than normal for tight corners and areas where you can’t access the baseboard very easily.

The good news is that those difficult to access parts of a building are usually also low-use and low-stress, so choosing smaller nails for those areas won’t compromise the structural integrity of the baseboards.

What Kinds of Nails Work Best For Baseboard Trim

Now that you know what factors you need to consider before choosing what size nails for baseboard trim, let’s talk about the most common options.

Brad Nails (18-Gauge)

18-gauge nails, the kind used in brad nailers, are some of the most common for attaching baseboards. They’re small, suitable for delicate materials, and are incredibly subtle on the finished baseboard. Brad nails also come with a variety of coatings that can make driving them easier, or can help protect the finished baseboard from staining.

Brad nails are affordable, effective, and can be driven quickly with a good nailer. But, there are a few downsides to this style of nail.

Brad nails are very thin, a tiny fraction of an inch wide. That means that they don’t offer a lot of strength and are a relatively weak attachment. You’ll probably need more brad nails than you would need of a thicker more durable option.

Another limitation is that brad nails tend to be a little shorter than finishing nails and other designs. That means that a brad nail won’t securely attach thicker and fancier molded baseboards. The longer brad nails that are available tend to be a little more expensive than standard sizes, and aren’t always compatible with a regular brad nailer. You need a nail gun that’s designed for longer nails.

Longer nails are also a little more likely to bend, both in the package and in your nail gun’s magazine. That makes jamming and misfires a little more common with long brad nails, another good reason to consider moving up a size if you need a longer nail.

Finishing Nails (15- and 16-Gauge)

Finishing nails are the other common size nail for baseboard trim. 16 gauge finishing nails are a little more common than 15-gauge, but they offer similar performance and durability.
Finishing nails are only slightly bigger than 18-gauge nails, but they are a fair amount stronger. That’s great because you can get a little more security and durability by using them, but don’t have to sacrifice the finished appearance of your baseboards in the process.

Finishing nailers are also incredibly common and tend to have a little wider compatibility than brad nailers, which means they are the more versatile tool. If you have to choose your nails based on the tools at hand, we’d recommend going with a finishing nailer and finishing nails thanks to that additional versatility.

While most people won’t recommend you use nails any larger than finishing nails, it is important to remember that sometimes you need a little extra support in some areas. While finishing nails are more durable and secure than brad nails, they’re still very small nails. You might need a larger option for some projects, and some parts of your baseboard.

Larger Nails and Hand-Driven Nails

We’re not going to go into too much detail about these options since they aren’t very common and are only occasionally necessary for baseboard projects.

Larger nails can be useful for the thickest kinds of baseboards, but they can be difficult to use with molding and ornate designs. That’s because they are more secure, but also more likely to damage or split the materials you’re working with.

Hand-driven nails are a good option if you need something much larger than a 16 gauge nail, but they also take a lot more time to use. Not to mention that hand driving a nail into delicate molding can take a lot of skill, and goes wrong quickly.

Neither of these types of nails should be used for the majority of baseboards or for the entire baseboard when they are used. But, both types and sizes can be a useful addition to your regular nail gun nails for tricky areas or places where you need a little extra durability.

Choosing the Right Length

In addition to thinking about the size of your nail (or its thickness), you should consider what length you need for the project. The most common lengths for baseboard are about 2 inches to 3.5 inches long. Longer nails are necessary for thicker baseboards, but you can use shorter options for a thinner baseboard.

Just remember that you want to make sure at least 1 inch of the nail is embedded in solid material behind your baseboard. That length will help keep the baseboard secure and will add durability to your work.

The Takeaway

Choosing the right size nail for baseboard trim can be a complicated process. There are many different factors to consider, and every project is a little different. Fortunately, with only two common sizes of nails for most baseboards, the selection isn’t as complicated.

If you have to choose the right size nails for baseboard trim ahead of time, or without all the information about the trim and the project, we’d recommend sticking the framing nails. You might need to do a little more finishing work to get a professional-looking baseboard, but the extra durability, stability, and versatility is worth it for most projects.