Have you ever wondered why graves sink?
Once a funeral is over and a loved one has been laid to rest, attention tends to turn to the headstone – this is natural as you no doubt feel it’s important to honour their life with a meaningful memorial.
You may believe that it’s a simple case of finding a suitable memorial – say, a headstone or a kerb set – writing an inscription, and then hiring the services of a reputable local memorial stonemason company to make the headstone and install it on the grave – however, in most cases you’ll find a cemetery or council telling you that you’re going to have to wait for the grave to settle.
A new grave takes time to settle and can be prone to sinking, so it’s unwise to place a headstone on a grave too soon.
This leads to many people wondering why that is the case.
Movie scenes would often have us believe that gravediggers dig the hole, conduct the burial, fill the hole in, and then that’s the end of that.
Maybe that’s how things were in the Wild West.
Unfortunately, nature and physics doesn’t allow things to be quite as straight forward as that in the modern world.
Not if we want our graves to be well maintained and to look as visually pleasant as possible, anyway.
Hopefully, this guide can address some common questions surrounding grave settlement by providing some in-depth answers.
How Long Does it Take for a Grave to Settle?
Most cemeteries and councils will typically advise that it takes at least 6-12 months for a grave to settle.
As a result, you will usually be asked to wait a minimum of 6-12 months before putting a headstone on a grave – though some may state that you should wait beyond 12 months.
The time it takes for a grave to settle can vary between cemeteries due to many factors, such as soil type or condition and the weather that the graveyard experiences over many months.
For this reason, there is no clear-cut, hard and fast rule as to when you can safely put a headstone on a grave.
You will find that many cemeteries and councils have their own strict rules that outline the minimum amount of time you must wait before erecting a headstone or other memorial, so do check with them directly.
In some cemeteries it may be possible for a headstone to be erected almost immediately if the memorial is to be installed onto an already existing concrete foundation, or within just a couple of months if it displays horizontally while flat on the ground.
Though do remember, not just anyone can put a memorial on a burial plot.
Waiting Before Installing a Memorial
For those who are told they must wait, they may feel guilty about not installing a gravestone for many months and for leaving the grave bare.
Perhaps they ‘d prefer to get things sorted as soon as possible so that people don’t think they have simply neglected the grave, or because the thought of buying a headstone leaves them feeling anxious and preferring to just hurry up and get things dealt with.
Whatever the reason for wanting to rush, it’s important to realise that being made to wait a little while is often no bad thing.
Waiting to choose a memorial gives us time to process our loss, gather our thoughts and ensure that the memorial and inscription that we do have crafted for our loved one is a fitting tribute to their life.
So, now that we know we should wait 6-12 months or longer before putting a headstone on a grave, we may wonder why this is the case.
The short answer is that new graves often sink, meaning cemetery staff must maintain them by topping them up with soil until the ground has completely stabilised, which may take many top ups over many months.
Installing a headstone on a grave too soon will likely result in the headstone leaning forward within a matter of months due to the movement of the soil within the grave.
Why Do Graves Sink?
While visiting a cemetery you may have noticed that some graves appear to have sunk – this is caused by something called grave subsidence.
This is completely normal and should soon no longer be a problem following a little TLC from the cemetery site workers, though it can cause the graveyard to look unsightly if the burial plots receive no maintenance or care for many years – the next time you pass a very old graveyard that’s fallen into disrepair, you should find it easy to spot signs of grave subsidence.
You may also notice some graves, especially new ones, have a large mound of soil piled up on top of them – this relates to the TLC the grave receives, but we’ll soon delve into that in more detail.
So, this all naturally leads us to question what is grave subsidence?
To understand what grave subsidence is, what causes it and why a grave requires ongoing maintenance, we need to first better understand what happens after a burial.
What Do Gravediggers Do After the Burial?
Once the burial has taken place, the grave is backfilled using the soil that was excavated from it.
Near the end of the backfilling process, the gravediggers allow a certain amount of ‘mounding up’ on top of the grave – this is the large mound of soil you may have noticed on recent burials.
This is in anticipation of the grave sinking caused by grave subsidence.
In most cemeteries, the ‘mound’ is created using a thick clay material, which is the soil excavated from the actual burial site.
In the weeks following the burial, cemetery staff are likely to conduct regular checks of all recently backfilled graves, while also monitoring all graves, both old and new, after any heavy rainfall.
If a new burial plot experiences grave subsidence, the cemetery will usually top up the plot until the soil has compacted naturally.
Some graves need to be topped up several times over the course of an entire year or more to combat grave subsidence.
Once a grave has stabilised, a layer of topsoil and grass seed can be placed over the grave and surrounding area to save the topsoil from eroding.
Grave subsidence can and will happen again over time without adequate care, so it’s important for a grave to be well maintained, either by yourself or through the services of a reliable grave maintenance company.
What is Grave Subsidence?
So, we’ve explained that grave subsidence is when the ground on top of a grave sinks in and that it’s a natural occurrence that should not be a cause for concern.
Just understand that the grave will improve and stabilise in time provided it’s given the appropriate attention.
What Causes Grave Subsidence?
Now, let us explain why grave subsidence occurs.
When a grave is excavated, the soil material within the grave is loosened.
This soil is often lumpy and irregular, particularly when it contains a high clay content.
Following the burial, the soil is replaced on top of the coffin to fill in the hole that was dug, but this results in the creation of many air pockets within the grave.
Over the course of weeks or months, a newly backfilled grave will more than likely begin to ‘sink’ as these air pockets escape and the soil compacts and settles.
This is completely natural and unavoidable – especially when there is rainfall.
It’s simply the process of air escaping and the loosened dirt and soil settling into place – due to gravity, this all happens with downward momentum, hence the grave appearing to sink.
The coffin will also naturally collapse over time, which further shifts the soil within the grave.
Common Factors that Cause Grave Subsidence:
- Soil type – for example, heavy clay soil can take longer to settle
- Nature and condition of the grave location
- Depth of the excavation
- Number of burials within the grave
- Heavy rainfall on the grave, or rainwater runoff
- Groundwater levels within the cemetery
Grave subsidence can be particularly bad following significant rainfall, or if rainfall occurs over a prolonged period of time.
Why Doesn’t the Cemetery Compact the Grave?
Those who are bereaved can experience a great sense of discomfort when they find grave subsidence has affected their loved one’s burial plot.
As it’s a natural occurrence, it affects all cemeteries and burial plots of all ages.
To minimise the risk of grave subsidence affecting a new burial plot would mean to physically apply sufficient pressure to the soil throughout the initial backfilling process at the time of burial.
Construction companies often use special machines to densely pack earth into holes that have been dug up while building foundations.
As you can imagine, this requires a lot of pressure meaning this method would not be appropriate at a cemetery as this would crush the coffin that’s buried below.
What Should You Do if You Notice Grave Subsidence?
It is understandable for the bereaved to feel distressed if they notice grave subsidence on the burial plot of their loved one – even if they understand that it is to be expected.
Naturally, people want grave subsidence to be rectified as soon as possible so that those laid to rest can do so within grounds that are well cared for and that look more aesthetically pleasing.
Furthermore, sinking graves can also be a trip hazard, so there are several reasons as to why we should report grave subsidence when we see it.
If you notice grave subsidence on a burial plot, it would be a good idea to notify the cemetery by telling them the location of the grave and the name on the memorial. This will ensure they can identify the grave and, if necessary, schedule the required maintenance work.
If you happen to use a memorial maintenance company, they should become aware of the grave subsidence during their next routine visit and immediately schedule the necessary works.
If the grave subsidence is causing you distress, don’t hesitate to contact your maintenance company to notify them.