Most coffins decompose. The process depends on:
- What the casket is made from
- How quickly the materials break down
- External forces such as earth, water, and creatures
- Internal forces as the body within decomposes
- Where the casket is interred, i.e. in the ground, a crypt, or mausoleum
It’s common to have lots of questions surrounding the process of death and what happens afterward. After the funeral, the deceased will either be buried or cremated.
It’s an intriguing question and, as always, one that does not have a clear answer. It depends on many factors. I’m going to look at all those in this article. So, if you are curious about whether caskets decompose, read on. I’ve got the facts for you right here.
The Casket’s Condition Depends on its Location

You could choose to be buried in:
- A plot in the ground: Provides a piece of ground within a graveyard where the casket is buried six feet underground in the earth.
- A mausoleum: An outdoor building, above ground. It allows caskets to be kept in a space above the ground, usually behind a door bearing the details of the decedent.
- A crypt: An underground room made from stone, installed beneath a church or similar building.
A traditional below-ground burial means the casket is lowered into the earth. You’d then put earth on top of the casket to bury it.
Over time, various things can damage the casket, such as:
- Water-logged earth
- Damp earth
- Bacteria
- Bugs, worms, and similar creatures
There is a lot going on beneath the surface, so a casket is likely to decompose faster buried in earth than if it was placed in a crypt or mausoleum.
The condition and location of the ground matters too.
Flooding would cause the ground to become waterlogged, flooding the caskets buried there.
Earthquakes cause movement too, likely damaging the caskets. Anything that affects the ground affects the caskets.
The earth above a casket can also sink over many years. The organic processes going on beneath, with the decomposition of the body taking place, can contribute to this. The earth packed in over the top of the casket can also settle over time.
That weight puts additional pressure on the casket, especially when it’s made from a cheaper wood product, such as plywood or veneer.
The Casket’s Composition Also Matters
Caskets are made from all kinds of materials. In order of the cheapest to the most expensive, you could buy one made from:
- Plywood
- Plywood covered in cloth
- Laminated plywood (where a thin layer of real wood is put on top of a cheaper layer of plywood)
- Steel
- Solid wood (usually a hardwood)
- Copper
- Bronze
You’ve also got other natural casket materials that are designed to be more eco-friendly. The best examples include willow and bamboo. These would obviously decompose far more quickly than anything else.
Indeed, these caskets are often selected by eco-conscious people who don’t want to cause any harm to the ground they are buried in.
The rule of thumb is that the cheaper the casket is, the more likely it is to decompose faster.
Compare a plywood coffin to one made from bronze, for instance. You can guess that the bronze one is going to hang around for many years, long after the plywood one has all but collapsed.
Burial Leads to Faster Decomposition

Think about it – the weight of the earth above the casket, the various bacteria, and other naturally-occurring factors going on… they all make a difference.
Wood is going to decompose far faster than anything else, though. If you were buried in a metal casket, it would likely begin to rust after a while. If it were dug up for some reason several decades into the future, it would look different to how it originally did. However, it would still be solid.
Your casket is also going to be buried in a natural place. It’s easy to walk through a graveyard and imagine bodies buried below the ground in great condition in pristine caskets. That’s not the case, though.
Any number of things could cause further damage to occur to a casket. For starters, caskets aren’t hermetically sealed. Many funeral homes offer caskets that include rubber gaskets. These are gaskets that provide a tighter seal when the lid is put on the casket.
There are three things to note about these gaskets, two of which influence the whether coffins decompose:
- They are not required by law
- They cannot preserve a body
- They speed up the decomposition process
The acceleration of body decomposition with the presence of a gasket is why it is not advised for bodies being interred in a mausoleum. Here’s why.
Caskets Can Potentially Explode
The build-up of gases inside the body must have somewhere to go.
If a casket is not hermetically sealed, the gases can escape the casket.
If it is sealed with a rubber gasket or similar sealer, those gases can build up to dangerous levels which can make the casket explode.
It is not unheard of for the front of a burial space inside a mausoleum to be blown off because of the pressure building up inside the space. That’s why a casket that arrives with a seal between the lid and the main portion of the casket will have the seal broken to minimize the chances of this happening.
The Body Speeds Up Coffin Decomposition
I should mention there are two forces that influence the condition of the casket:
- External forces
- Internal forces
So far, I have covered external forces. I have yet to mention the effects the body inside the casket has on the casket itself.
While embalming is not required by law, many people opt to have it done. It slows the rate of decomposition but cannot hold back nature, so it will eventually take place.
As the body decomposes, it goes through many changes. These begin immediately after death and continue for some time. The process does slow down once the soft tissues have broken down and vanished, though.
The amount of time taken depends on whether the body was embalmed and what type of coffin it was buried in.
One source stated that it would take approximately eight to 12 years for a body that had not been embalmed to reach the skeletal stage if it hadn’t been buried in a casket.
However, the initial stages of decomposition are faster. It only takes two or three days for bacteria to begin doing their work. You may know the human body is made up of approximately 70% water. That liquid is no longer required to keep you alive. So, it leaves the body by whatever means is necessary.
This means the liquid caused by decomposition will start to leak out into the casket. This happens regardless of where and how you are buried. From mausoleum to crypt to in the earth, you can be sure this process always occurs.
Body Decomposition Ages the Casket
All those fluids and gases lead to a huge number of maggots, bacteria, and other things to get to work. This affects the condition of the casket, too.
There have been cases where coffins buried in the ground have collapsed under the weight of the earth abovethem.. Cheaper plywood caskets are far more likely to do this than ones made from hardwood, however.
The rule of thumb is that the longer lasting the casket materials are, the less effect the surroundings will have on them if buried in the earth. That applies to decomposition and what is happening outside the casket.
Caskets Can Still Be Damaged Inside Mausoleums
It’s clear by now that your casket will last far longer if made from steel or bronze and it is interred above ground in a mausoleum.
However, even then, there is a chance water could get inside the portion of the mausoleum that your casket is interred inside. This would have the same effects on the condition of your casket than if water got to your casket in any other way.
In conclusion, no casket is immune to the effects of water, soil, air, and other elements that interact with it. No two graves are identical. No two mausoleums or crypts would present the exact same conditions for a casket to be interred in.
This means there are always differences in the rate at which a casket would break down. Even a bronze casket would age more quickly in damp conditions compared to much drier ones, for example.
And in most cases, you would never know how long a casket had lasted.

Sources:
https://www.businessinsider.com/how-long-it-takes-human-body-decompose-grave-coffin-2019-8
http://www.memorialpages.co.uk/articles/decomposition.php
https://en.wikipedia.org/wiki/Burial_vault_(enclosure)
https://www.elementalnw.com/faq/how-long-will-caskets-last/
https://trustedcaskets.com/blogs/news/how-is-a-body-placed-in-a-casket-and-secrets-of-funeral-homes
https://www.grunge.com/171142/what-happens-to-your-body-after-one-year-in-a-coffin/
https://www.everplans.com/articles/all-you-need-to-know-about-caskets