Are Coffins Nailed Shut? How Are Coffins Sealed and Why?

Burying a loved one is one of the most difficult challenges we will face. From alerting friends and family to choosing between a casket and a coffin, the process can raise many questions about what to expect. So what can you expect after your loved one is placed in a coffin?

Coffins are not nailed shut anymore, although this used to be common. Instead, funeral directors now seal coffins with a lock and a rubber gasket that ensures the coffin stays closed. Sealing coffins is not necessary but can have benefits.

Let’s talk more about how coffins are sealed and why it is common practice. I’ll also touch on some common myths about sealing coffins, so be sure to read until the very end!

Why Would Funeral Directors Seal a Coffin?

Funeral directors seal coffins in order to protect the body of the deceased, but not for the reason you may think. Sealing coffins helps prevent the body from falling out of the coffin during transportation.

Let’s talk more about why it is common to seal coffins and why it may be the right choice for your loved one.

Protecting the Body

Sealing a coffin can help protect the body from moving around too much or coming out of the coffin. Overall, this may not seem very important, but it is vital to prevent accidents during transportation.

The average coffin weighs, on average, 150 to 250 lbs (68 to 113 kg) without the body inside. 

Keep in mind that the coffin is how they will bring the body of your loved one to the service. So, people will need to carry the coffin at least a few times during the process. Accidents can happen during the process of carrying the coffin.

If the funeral home employees or the pallbearers drop the casket, this can cause the body to come out, which could be upsetting for family and friends to see their loved one’s body fall out of the coffin. 

So, sealing the coffin can help keep the body safely inside even if they drop it.

Protecting the Environment

Sealing a casket can protect the body during the service, but it can also protect the environment from the body. The embalming process involves injecting a fluid into the deceased’s body to help preserve them for the funeral. 

Embalming fluid contains chemicals like formaldehyde, which are not good for the environment. 

These harmful chemicals begin to leak out of the body during the decomposition process, and a sealed coffin can help those chemicals stay inside of the coffin rather than leaking out. The embalming chemicals can then seep into the groundwater. A sealed coffin is better able to hold those chemicals as the body decomposes. 

While this is a great way to keep embalming chemicals out of the environment, it is not a perfect solution. 

Since coffins tend to be made of wood, sealing them may not be enough to keep the chemicals inside. Wood can begin to break down over time, especially when exposed to outside elements. So, the fluid may still leak if the coffin begins to break down. 

Does Sealing a Coffin Preserve the Body?

Sealing a coffin does not preserve the deceased’s body. While sealing the coffin can help keep environmental elements from entering, it doesn’t stop the decomposition process. Like everything buried in the ground, the body will decompose over time.

While it may be a common misconception, sealing a coffin actually does not help preserve the deceased’s body after the burial. 

As discussed above, sealing the coffin can help prevent outside elements from getting inside the coffin, but decomposition happens regardless. In fact, the lack of air and moisture can actually speed up the decomposition process. 

One major factor that slows down decomposition is temperature. The reason that so many funeral homes refrigerate dead bodies is that the cold temperature will slow down the decomposition process. 

Sealing the coffin does not affect the temperature inside the casket enough to prevent or slow down the decomposition process. 

woman with white lily flowers and coffin at funeral in church

It is a common misconception that bodies not exposed to oxygen won’t decay as quickly. This is not true as bacteria in our body are able to spread and continue the decomposition process even without the presence of oxygen. 

Cutting the body off from oxygen with a sealed coffin only allows the bacteria that cause decomposition to spread faster since there is nowhere else for it to go. Rather than the bacteria spreading to the ground outside of the casket, it will fester inside of the casket, attacking the body faster and more efficiently, leading to faster overall decay. 

No matter where you purchase a coffin from, it is the seller’s responsibility to be clear about the limitations. This means that they should not promote that a sealed coffin prevents decomposition or slows it down. 

So, if you choose a sealed coffin, know that it won’t preserve the body of your loved one. 

How Is a Coffin Sealed?

We typically seal coffins shut with a locking system that allows the funeral director to lock and unlock them as necessary. Coffins no longer need to be nailed shut in order to help protect the body.

People used to seal coffins by nailing them shut. This was a quick, effective way to ensure the lid would not come off during the burial and transportation. But just like other aspects of the funeral industry, we have come far enough to surpass the need for nails. 

Instead, coffins are held together by a gasket which seals the top and bottom parts of the coffin together. You can control the gasket by a locking mechanism usually found at the foot of the coffin. When the funeral director turns the mechanism, they seal the coffin shut, allowing for safer transportation. 

Can You Bury Someone Without a Sealed Coffin?

You can bury a casket without sealing it. Though this may make the transportation and burial process a little more difficult, sealing is not a requirement. Some cemeteries may require you to purchase a burial vault for a sealed or unsealed coffin.

Different cemeteries have different rules when it comes to burying a loved one. Sometimes, cemeteries may require a burial vault for any casket or coffin they bury. While this is not a universal requirement, it is quite common. If you want some more information about burial vaults, check out our article here

If a cemetery requires this addition, then whether or not you seal the coffin will be irrelevant after the burial. Sealing a coffin, especially one made of wood, is not going to prevent the body from decomposing or prevent the coffin from collapsing. Coffin collapsing is a common phenomenon that occurs with wood coffins when there is too much-added pressure. 

Sometimes the dirt is too heavy to allow the coffin to hold its shape. So, they may collapse under the pressure of the dirt or the weight of machines traveling over the grave. A vault can help keep the coffin in one piece. Sealing the coffin does not affect whether or not it will collapse underground. 

Different rules may apply to different cemeteries regarding vaults and sealed coffins, but one way around these rules is to bury your loved one on private property. Doing this allows you to use any container of your choosing when burying your loved one without restrictions about seals or vaults. So, consider this if you want to use a coffin. 

What’s the Difference Between a Casket and a Coffin?

The main difference between a casket and a coffin is the shape. Caskets have four sides and are rectangular. Meanwhile, coffins have six sides creating a unique hexagonal shape that fits around the body. 

While some people use casket and coffin interchangeably, this is actually incorrect. A coffin is typically made of wood and has a unique shape. Overall, caskets are a more common way to bury a loved one compared to a coffin, but both are valid options. 


Another major difference between the two is the lids. Casket lids have hinges that allow them to sit open during a funeral service so the family can view the deceased’s body. Casket lids come in full-couch and half-couch options for the funeral service. 

Full-couch is a lid with one solid piece, while a half-couch allows only half the lid to open at a time. 

Half-couch caskets are more common and are featured heavily in pop culture. So, you are probably more familiar with that style. It covers the feet and legs of the deceased, so the family can focus on the upper body during the viewing. 

Coffins do not have lids on a hinge. Instead of opening like a casket, coffin lids do not open like a flap. Rather, coffin lids come completely off when opened as they are not attached. Ultimately, this makes closing and opening the coffin more difficult, and people often choose to seal coffin lids to keep them on securely. 


Historically, coffins were the only option for burying your loved one in a container. During the early years of coffin use, they were saved for only the wealthy to bury their loved ones. However, as their popularity grew, coffins became more accessible to everyone who lost a loved one. 

During the time of the spiking popularity of coffins, it was common to bury the deceased without much decoration or added style. When embalming became more popular during and after the Civil War, people became more interested in glamorizing the process of burying a loved one. This was when caskets began to take over coffins. 

Caskets are a lot less basic than coffins. They have features like lids and intricate designs that make them more glamorous. Once caskets began to take over, people began to view coffins as too basic and cold. So, coffins dropped in popularity as caskets began to rise. As we can see now, caskets continue to become fancier with more added details. 

Why Are Coffins Hexagonal in Shape?

Coffin manufacturers have made them that unique shape to better accommodate the body. This helps save on costs during the manufacturing process because they require less wood to complete. 

If you look at the unique, hexagonal shape of a coffin, you can see how it better suits the shape of a body at rest. The very top of a coffin is thin in order to accommodate the head of the body. From there, the sides of the coffin come out at a more broad angle. Manufacturers designed them this way to accommodate the wide shape of the shoulders. 

As you get to the bottom of the coffin, you can see the body begins to thin out again. This shape accommodates the body very well in its design and creates a more snug fit for the body. While not everyone may like the shape, a coffin is a much more simple, efficient design for the body. 

Caskets are rectangular in shape, which requires more materials to make. Though some may prefer the less-detailed, rectangular design, caskets can be easier to handle when carrying because of the shape compared to a coffin. 

Overall, manufacturers designed coffins with the ordinary shape of a human body in mind. This design may not be reasonable for every body type. One size certainly doesn’t fit all when it comes to coffins and even caskets. So, the unique shape may not be realistic for everyone to use. 

Final Thoughts

Despite the history of sealing a coffin with nails, this is no longer a common occurrence. Now, coffins have seals of their own that hold the top and bottom of the coffin together. The lack of hinges on a coffin makes it challenging to manage without a seal. 

Overall, caskets have taken over the mainstream funeral business, but coffins are still available at most funeral retailers. Make sure your loved one can fit the unique shape of the coffin before making your choice. 


Was this post helpful?

Useful? Save information for later by printing or sharing.

Alex Noel

Hi there! I'm Alex Noel and live in Indianapolis, Indiana. I started this website to share my experience. My goal is to provide Americans a more fulfilling goodbye.

Recent Posts

Table of Contents