Foam filling is used to make redundant tanks, pipework and voids safe without always needing full excavation or removal.
It is commonly used when a tank or underground structure has reached the end of its working life but cannot be easily or safely removed from site.
This may be because it is:
- underground
- close to buildings
- beneath hardstanding
- near services
- difficult to access
- costly or disruptive to excavate
Foam filling can be used as part of a safe decommissioning process. It helps fill the empty space inside a tank, pipe or void, reducing the risk of collapse, vapour build-up or future ground movement.
It can also be useful where a site needs to be reused, landscaped or made safe without major disruption.
Why foam filling is used
Making redundant tanks safe
Once an oil or fuel tank is no longer in use, it needs to be dealt with safely.
In some cases, the tank can be removed completely. In others, it may be better to fill the tank in place.
Foam filling is often used to:
- make the tank inert
- support the tank structure
- reduce the risk of the ground caving in
- absorb or encapsulate residual hydrocarbons
- prevent flammable vapours from building up
- avoid unnecessary excavation
Before foam filling takes place, the tank should be assessed and prepared correctly.
This may involve removing leftover fuel, sludge or waste and checking that the tank is suitable to be filled.
Reducing disruption on site
Foam filling is particularly useful where full removal would cause disruption.
This may apply if the tank is located:
- under a driveway
- beneath a yard
- close to a building
- near foundations
- next to underground services
- in a restricted access area
In these situations, excavation may be expensive, time-consuming or potentially damaging.
Foam filling allows the tank or void to be made safe in place, which can reduce the need for heavy machinery, hardstanding removal or large-scale groundworks.
Helping with environmentally responsible decommissioning
Foam filling may also be considered where reducing ground disturbance is important.
When carried out correctly, it can help limit excavation and reduce the chance of residual material affecting the surrounding soil or groundwater.
We cover this in more detail in our related blog on whether foam filling is an environmentally friendly way to decommission a tank.
Common places foam filling may be used
Foam filling is often associated with oil and fuel tanks, but it can also be used in other redundant spaces.
It may be suitable for domestic, commercial and industrial sites.
Common applications include:
Fuel and oil tanks, including underground and commercial tanks
Redundant pipework and pipelines
Service ducts and chambers
Voids beneath roads, yards and hardstanding
Inaccessible cavities and enclosed spaces
Redundant underground structures
Foam filling for tanks
Foam filling is commonly used for tanks that are no longer required.
This can include:
Domestic heating oil tanks
Commercial diesel tanks
Underground storage tanks
Tanks beneath yards or forecourts
Tanks that are difficult to remove safely
The aim is to make the tank safe and stable so it can remain in place without creating unnecessary risk.
Foam filling for voids
Voids can sometimes be left behind around tanks, ducts, chambers or redundant structures.
If they are not dealt with, they may lead to ground movement, instability or future maintenance issues.
Foam filling may be used to fill these spaces where excavation is not practical.
Examples include:
- voids under concrete
- spaces beneath hardstanding
- redundant service channels
- cavities around old infrastructure
- difficult-to-access underground areas
Foam filling for pipework
Old pipework may also need to be filled if it is no longer in use.
This can be useful where redundant pipe runs cannot be easily removed or accessed.
Foam filling may help to:
- seal unused pipework
- reduce internal voids
- prevent movement or collapse
- make the pipework safe
- avoid unnecessary excavation
Foam or concrete filling?
Foam and concrete filling can both be used, but the right option depends on the site.
Foam is often useful where a lighter material is preferred or where the filled structure may need to be removed later.
Concrete may be used where a heavier, more permanent fill is required.
The choice can depend on:
- the size of the tank or void
- access to the site
- the condition of the structure
- future use of the area
- whether removal may be needed later
- the level of stability required
Our related blog on where foam and concrete filling can be used looks at this in more detail.
Foam filling, removal or excavation, which route fits the site?
Foam filling is not always the right choice.
Sometimes full removal is the better option. In other cases, excavation may be needed, especially if there is contamination or the site is being redeveloped.
The right route depends on the tank, the site and what the area will be used for afterwards.
Foam filling may be suitable when:
- the tank is underground
- access is restricted
- removal would be disruptive
- the tank is close to buildings or services
- excavation could damage hardstanding or landscaping
- the structure can safely remain in place
- future removal may still be possible
- the site needs to be made safe quickly and practically
Tank removal may be better when:
- the tank is easy to access
- the tank is damaged or corroded
- the site needs to be fully cleared
- the property is being sold
- the client wants the tank removed completely
- redevelopment plans require open ground
Excavation may be needed when:
- a leak has occurred
- contaminated soil is present
- the tank cannot be safely filled
- the surrounding ground needs remediation
- construction work requires full clearance
- environmental checks show further work is needed
What to consider before choosing foam filling
The condition of the tank or structure
A specialist should check whether the tank, pipework or void is suitable to be filled.
This may include looking at:
-
- structural condition
- access points
- signs of corrosion
- signs of collapse
- surrounding ground conditions
- whether the structure can safely remain in place
What the tank or pipework previously contained
The previous contents of the tank are important.
This may include:
- heating oil
- diesel
- petrol
- gas oil
- sludge
- contaminated water
- residual fuel
The contents can affect how the tank is cleaned, how waste is removed and what safety measures are needed before filling.
Whether contamination is suspected
Foam filling may not be suitable until contamination risks have been checked.
Warning signs can include:
- fuel smells
- stained ground
- visible leaks
- damaged pipework
- contaminated water
- poor tank condition
- previous fuel loss
If contamination is found, removal or remediation may be required before the site can be made safe.
Future plans for the site
The future use of the area is one of the most important factors.
Before choosing foam filling, consider whether:
- the area will be landscaped
- the ground will remain as hardstanding
- the site will be sold
- building work is planned
- excavation may be needed later
- the tank may need to be removed in future
Foam filling can be a practical option where the structure can safely remain in place. However, it may not be the best route if the site needs to be fully cleared.
Foam or concrete
Foam and concrete are both used for filling, but they have different advantages.
Foam may be preferred where:
- access is limited
- a lighter material is useful
- disruption needs to be reduced
- future removal may be possible
- the structure needs to be filled quickly and safely
Concrete may be preferred where:
- a heavier fill is required
- a permanent solution is needed
- structural stability is the main priority
- future removal is unlikely
A site survey will help determine which method is most suitable.
Foam filling services from LV Fuel Services
At LV Fuel Services, we provide professional tank decommissioning, tank removal, fuel removal, foam filling and concrete filling services for domestic and commercial clients.
Our team can assess your site and advise whether foam filling, concrete filling, full tank removal or excavation is the most suitable option.
We can help with:
- site surveys
- fuel and oil removal
- tank cleaning
- tank decommissioning
- foam filling
- concrete filling
- tank removal
- contaminated waste removal
- soil sampling and remediation
If you are unsure which route is right for your site, get in touch with LV Fuel Services to request a quote or make a booking.
Related Blogs
Key questions before deciding
Before choosing foam filling, removal or excavation, it is worth asking:
- Is the tank above ground or underground?
- Can it be accessed safely?
- Is there any sign of leakage?
- Has the tank been emptied and cleaned?
- Is the tank structurally sound?
- Will the site be built over?
- Will future excavation be needed?
- Would removal damage the surrounding area?
Where an oil tank is difficult to remove, filling it in place may be the most practical option.
However, where access is straightforward and the site needs to be cleared, removal may be more suitable.
We explain this further in our related blog on when an oil tank should be filled instead of removed.
Environmental and site reuse considerations
Limiting ground disturbance
One of the main reasons foam filling is chosen is to reduce disruption.
Removing a tank can involve:
- breaking up concrete
- excavating soil
- using heavy machinery
- disturbing nearby services
- damaging landscaping
- creating additional waste
Foam filling can avoid some of this work by allowing the tank or void to be made safe in place.
This can be helpful on domestic, commercial and industrial sites where access is limited or the surrounding area needs to remain in use.
Managing contamination risks
Foam filling should not be used to ignore contamination.
If a tank has leaked, the site may need further investigation before any filling work is carried out.
This could include:
- tank inspection
- fuel and sludge removal
- vapour checks
- soil sampling
- contaminated waste removal
- remediation work
Any residual fuel or hazardous waste should be handled correctly by an authorised specialist.
Preparing a site for future use
Foam filling may be useful where the area will remain in use but the tank, pipework or void is no longer needed.
This may include sites being used for:
- parking
- hardstanding
- landscaping
- light commercial use
- domestic access
- general site reuse
If the area is due to be heavily redeveloped, excavated or built over, removal may still be the better long-term choice.
This is why the future use of the site should always be considered before a filling method is chosen.
For more detail on the environmental side of the process, read our related blog on foam filling and environmentally friendly tank decommissioning.
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