Frequently Asked Questions for Oil Tanks:

Do I need a bunded tank, and how do I know?

All non-domestic oil storage tanks over 200 litres need to be bunded.
Located in Wales - yes you need a bunded tank.
For domestic premises in England Scotland, you need to carry out an oil storage risk assessment (this can be obtained from OFTEC - form TI/133D).

In brief a Bund is required in domestic situations if:
You are storing over 2500 litres.
Your tank is near an open drain or loose fitting manhole.
Your tank is within 10m of controlled water such as a river, stream etc.
Your tank is located where any spillage could travel over hard ground to reach controlled water.
Your tank is located within 50m of a borehole, spring or well.
Your tank vent is not visible from the fill point. (Such as an extended fill point)
Your oil use is for a building other than a single family dwelling.
Any other unique hazards to your site.

A good leaflet for reference is the OFTEC Home Guide to Domestic Oil Storage up to 3500 Litres

Which Tank Is Better, Plastic or Steel
Steel tanks can offer a much higher storage capacity and can be made to any dimensions, various specifications, offer increased protection from accidental damage, further protection against theft through drilling, and can have a longer lifespan (if maintained correctly).

Plastic tanks are approved in one design so cannot be altered in shape or dimensions, they are more easily moved, generally cheaper to purchase and install, and are less vulnerable to leakage when produced in a seamless, bunded design. Whilst it is important to ensure that a plastic tank is somewhat protected from the elements and UV exposure depending on the type of plastic it is made from, steel tanks must be maintained in the form of painting or treatment in order to prevent rusting. Both types of tank must be inspected on a regular basis to ensure any signs of damage or leakage are caught early.

What is a bunded tank?
A Bunded Oil Tank is simply a tank within a tank. The fuel is stored in the inner tank and the outer tank acts as a failsafe so that in the event of a spillage, excess fuel will collect in the bund. They are an absolute requirement at commercial, industrial and institutional premises. In some circumstances in domestic situations it is still possible to use a single skin tank (see below).

What materials are plastic oil tanks manufactured from?
All plastic oil tanks supplied by The Tank Shop are manufactured from Medium Density Polyethylene (MDPE) - a material that displays excellent chemical and impact resistance properties, making it ideal for external fuel storage.

Fittings vary according to tank type and supplier. However, in general fill points are made from either coated mild or stainless steel, outlets from coated mild steel, and vent points are manufactured from plastic. All materials used in the manufacture of oil tanks supplied by The Tank Shop are resistant to the potentially damaging long term effects of fuel.

What is a Single Skin Tank?
A Single Skin Oil Tank consists of a single container in which fuel is stored. Unlike bunded oil tanks and bunded fuel tanks, single skin oil tanks incorporate no secondary containment whatsoever and in the event of a spill, a pollution incident will occur.

Single Skin Oil Tanks are not suitable for the storage of fuel at commercial, industrial or institutional premises; or at domestic installations with an installed capacity of over 2,500 litres - unless installed within a suitably bunded area. For all other installations, an Oil Tank Risk Assessment must be undertaken by a competent person prior to installation and in accordance with the requirements of OFTEC Technical Instruction Book 3.

In anticipation of future possible regulations, serious consideration should be given to fitting a Bunded Tank, even where a single skin tank may currently suffice.

Are plastic oil tanks designed to protect from the damaging effects of sunlight?
Yes. Every plastic oil tank sold by The Tank Shop is manufactured from a material which incorporated UV inhibitors. These prevent UV rays from permeating the structure of the tank, thus preventing fuel degradation.

Are plastic oil tanks fitted with sludge valves / cocks?
No. Today, no openings (other than the tank outlet) are permitted below the maximum level of fuel in any oil tank. This reduces the risk of accidental spillage. In the event that contaminants (e.g. water) need to be removed from an oil tank, they should be removed by an appropriately licensed contractor via the inspection aperture fitted to each tank.

Are plastic oil tanks suitable for use with oil fired cookers?

On warm days there is a slight smell of oil from my oil tank. Why?
This is perfectly normal and is simply the fuel venting through the weatherproof vent fitted to the oil tank.

Should I replace older metal tanks?
Yes. It is important to replace older metal tanks as condensation, amongst other things, on the inside of the tank can cause corrosion, resulting in leaks and an expensive clean ups for the tanks owner.

What is the life expectancy of an oil storage tank?
Most plastic bunded oil tanks come with a 10 year manufacturers’ warranty and when properly installed and maintained can last for many years beyond its expiration date. 

How close to a boundary can I place an oil storage tank?
If the oil tank has a nominal capacity of less than 3,500 litres, it should not be placed any closer than 760mm to a boundary. This assumes that there are no flue outlets or buildings between the tank and the boundary. Where these distances cannot be achieved, the protection measures noted in OFTEC Technical Instruction Book 3 and British Standard BS5410 must be provided by means of a 30 minute fire resistant wall which extends a minimum of 300mm above and beyond the ends of the oil tank.

For oil tanks with a nominal capacity of 3,500 litres or greater please contact your local Building Control Officer or OFTEC.

How close to a flue outlet can I place an oil tank?
Oil tanks with a nominal capacity of less than 3,500 litres should not be placed within 1.8 metres of a flue outlet. Where these distances cannot be achieved, the protection measures noted in OFTEC Technical Instruction Book 3 and British Standard BS5410 must be provided by means of a 30 minute fire resistant wall which extends a minimum of 300mm above and beyond the ends of the tank.

For oil tanks with a nominal capacity of 3,500 litres or greater please contact your local Building Control Officer or OFTEC.

What are the base requirements for plastic oil tanks?
All plastic oil tanks must be installed on a flat, level and fire resistant base capable of supporting the weight of the tank when fully laden. If concrete slabs are used they should be a minimum of 50mm thick. The base should extend at least 300mm beyond the widest points of the tank and fully support the base of the tank in its entirety. Piers are not suitable for this purpose and can cause irreparable damage to the tank.

Can I install a tank in a building, garage or shed?
Internal oil storage tanks should never be installed in a habitable area, and should always be contained within an enclosed chamber.

Detailed requirements exist for the installation of oil storage tanks within habitable buildings and domestic garages. For more information, contact OFTEC.

Can I fit the tank myself?
Oil tanks need to be installed by a competent person, if you do not use an OFTEC registered installer, you will have to contact your local building control.

Who are OFTEC?
OFTEC is Oil Firing Technical Association for the Petroleum Industry. It was launched in April 1991 to construct a framework within which oil firing in the United Kingdom and Republic of Ireland could operate with a greater degree of technical expertise and efficiency. One of its first priorities was to set up a system of training and registration for Technicians engaged in commissioning, servicing, installation and plant operation with oil firing equipment. The scope of the scheme has since been extended to cover Technicians engaged in oil delivery.

How can I locate an OFTEC registered installer?
You can find an OFTEC registered installer by using the following website  link

Can I fit a sight gauge to a Bunded Tank?
No. Please note however that some bunded tanks are pre-supplied with an electronic oil tank contents gauge, which removes the requirement for a sight gauge to be fitted.

There is a two pin type socket fitted to my oil tank. What is this for?
This permits an LRC enabled delivery driver to plug in his overfill prevention equipment and is not for consumer use.

Are Plastic Waste Oil Tanks suitable for the disposal of petrol or any other highly flammable liquid?
No. For advice on how to dispose of petrol and any other similarly dangerous liquids, please contact your local authority.