How are caskets sealed? Are caskets waterproof? Common questions answered.

Should you be in the situation where you have to buy a casket, one of the many things you’re going to notice is the sealing/non-sealing of the coffins. Obviously, there's a difference in the price between the two types, so it makes perfect sense to wonder if sealing is necessary.

Is there a reason for sealing caskets?

Caskets will still look like regular ones with half-couch or full-couch format, but they will have the sealing property as well. There are several reasons for which the caskets will be sealed. Keep reading to find out the most important ones:

For reducing the risk of leakage

If you need to transport the body by air, the majority of airline companies will require you to have the body embalmed or placed in a sealed container. The sealing will reduce the risk of any liquids to escape throughout transportation.

For protecting the body

People have always tried to protect the body of the deceased for a long time. It's an attempt to care for it even after death. Caskets, be they of metal or wood, are sealed so that they protect the body. The sealing will keep the elements, air, and moisture from getting inside the coffin.

For sanitary reasons

Sometimes, the casket has to be sealed for lowering the risk of infection or contagion when the deceased has died of a contagious disease.

What are the benefits of sealing the casket?

Sealing the casket is necessary for some situations, so here are the most significant reasons to do it:

For protecting the content of the casket

People caring for the person that died would feel better at the thought that nothing will happen to the body any time soon (even if maintaining a body as it cannot be done). Sealing the casket will not allow bacteria, soil, or moisture to get inside the casket. Sealed coffins are a perfect choice for people trying to ensure a well-protected resting place for the deceased.

For protecting the environment

Truth be told, contagious diseases occur a lot less nowadays. Back in the days, when someone would die of a contagious illness, the sealed casket would maintain any source of illness inside the casket. It would reduce the risk for bacteria, viruses, and germs to escape, infecting other people, groundwater, or the soil.

In addition, embalming of the bodies includes the use of toxic chemicals that can harm the environment. Therefore, it’s another reason for which caskets should be sealed.

Are there any downsides for sealing the caskets?

More often than not, people will seal the casket in an attempt to prevent decay and preserve the body forever. The reality is that the bodies will decompose naturally, on the cause of internal processes in the body. Sealing the casket isn't going to stop the decay from happening.

As a matter of fact, there are a couple of downsides when it comes to sealing the casket:

Sealing increases the pressure

When the body is embalmed, it also contains anaerobic bacteria that will cause naturally emit gases. Should the coffin be sealed, the gases will build up in time and release pressure on the body, which only speeds up the decay. Worst case scenario, the internal pressure caused by the gasses will make the casket distort the shape, breaking the seal from the inside.

Sealing retains moisture

Unlike what some people may think, moisture doesn't get inside only from the outside. It\s also the contents of the casket that lead to moisture after some time. Should the casket be sealed, the humidity will build up and decay the body. If the coffin wouldn't be sealed, the moisture will evaporate.

Are all caskets sealed?

Nine times out of ten, it's only the metal caskets that are sealed. With wood being a porous material, it makes perfect sense that sealing a wooden coffin wouldn't eliminate the risk of moisture affecting the casket or the body. It’s only a matter of time until a wooden casket will break down in the soil, returning to nature.

On the contrary, metal caskets will need a lot more time for breaking down (all caskets do, eventually), and it seems that they need even a couple of centuries for biodegrading. Moreover, it’s possible to coat metal caskets with finished that reduce the risk of rust and corrosion. They can be made of metals with different thicknesses, which only makes them longer-lasting and crush-proof.

Sealing a metal casket means that the body and contents inside will remain intact. Everything that is inside a sealed metal casket will be protected as the environment is safe for centuries.

On a general level, the eco-friendly caskets and coffins are rarely sealed as it would defeat the primary purpose. They are supposed to break down and return to the soil together with the body. Everything, body, and casket, will become part of nature one last time. 

Is it difficult to seal a casket?

Now that it's clear that it's only the metal (or anything similar) that is sealed, we should also look into details. A rubber gasket will go all the way around the edge of the lid of the casket. Once the lid is closed, a sealing key (found on the foot of the coffin) will be turned, locking the lid safely in place. Therefore, the rubber gasket will create an air-tight seal. The mechanism resembles any other rubber gasket around a lid, and the seal reduces the risk of air and moisture to get through the casket.

Another thing that we should mention is that no casket will remain sealed until the end of time. Even the rubber is going to dry out and lose its elasticity. It can also lose its properties in moist conditions. Some metals will corrode after some time, losing strength. They're highly vulnerable in a place like the hardware fitting attachment points or screws. Imperfections of the finish can also affect the durability of the caskets.

Should you be determined to protect and preserve a body forever, a sealed burial vault will be a better choice.

What’s the story with anaerobic bacteria?

Bacteria that cannot grow or live when there’s oxygen is known as anaerobic bacteria. Once oxygen is eliminated (like in the case of sealed caskets), the bacteria will have the possibility to increase.

According to some, the sealed caskets may actually affect the whole decomposition process, making the corpse liquefy and decay. It's the gasses generated by the body in a sealed environment that will create pressure and anaerobic bacteria.

As the pressure rises, especially if the temperatures are high, the casket will turn into a pressure cooker. Eventually, it’s going to burst because of all the collected gasses and fluids of the body. It’s what some call the “exploding casket” syndrome.

Many states that allowing a bit of air to get inside the casket will dehydrate the body more efficiently. It's going to lead to cleaner skeletonization and decomposition.

It's entirely true that sealed caskets will preserve the body for a longer time than the unsealed caskets.

Are the sealed caskets expensive?

Obviously, the sealed caskets are pricier than the unsealed types. Even if the rubber seal is only $8, it’s going to add at least $800 to the final price of the casket. High-end sealed coffins can come for even $20,000.

All in all, you need to give it a good thought before spending the extra-buck for a sealed casket.

What’s the conclusion?

When someone dies of a contagious infection, it's almost mandatory that you use a sealed casket. You want to keep the risk of disease to zero.

Some people are trying to protect their loved ones even after death, thinking that preserving the body with a sealed casket is the perfect solution. It all comes with a price, though, and one should make sure that a sealed casket is what they truly want.

At the end of the day, everything will return to nature, and it's only a matter of time until it happens. It takes a couple of centuries in the case of sealed caskets (and the contents of course), but it's not avoidable, nevertheless.

  Blog Author: Tim