Information and advice for anyone who uses heating equipment at home
or work and is off the mains gas network
Domestic oil tanks and storage
The information on this page applies to oil storage tanks up to 3,500 litres capacity supplying oil to single family dwellings for heating and cooking purposes. For information on larger tanks, or non-domestic sites such as churches or village halls, please contact OFTEC’s technical team the number at the foot of this page or email email@example.com. Depending on where you live, regulations may vary slightly. The information here is a general guide, and you should check with your nearest OFTEC registered technician which regulations affect you.
About your oil tank
Modern oil storage tanks come in all shapes and sizes and can be made from plastic or steel. The size and type that your OFTEC registered technician recommends will depend on your individual requirements. It is recommended that the chosen tank is manufactured to OFTEC Standards (OFS T100 for plastic or OFS T200 for steel). A list of tank manufacturers can be found in the Equipment Directory on the OFTEC website at www.oftec.org
Your oil tank should be inspected annually as part of your heating system’s regular service visit. Oil tanks, like all heating products, have an expected working life (typically 20 years) and, if used beyond this time, the risk of a costly tank failure increases. The tank manufacturer or your servicing technician can advise you on when you should consider replacing your tank.
Protecting the environment
To minimise the risk of pollution from an oil spill, some installations must have secondary containment (a bund). This can be achieved by either choosing an integrally bunded tank or constructing a bund around a tank. The bund must be capable of holding at least 110% of the tank’s contents.
Your OFTEC registered technician will be able to advise whether you need a bunded tank using a standard risk assessment. Typically, installations near a river, well or any controlled water are likely to require bunding.
It is unlikely that a fire could be started by a domestic oil storage tank and its contents. However, tanks are required to comply with fire separation distances in order to adequately protect the stored fuel from a fire or heat source, that may originate nearby.
Tanks should be sited:
- 1.8m away from non-fire rated eaves of a building
- 1.8m away from a non-fire rated building or structure (e.g. garden sheds)
- 1.8m away from openings (such as doors or windows) in a fire rated building or structure (e.g. brick built house/garage)
- 1.8m away from oil fired appliance flue terminals
- 760mm away from a non-fire rated boundary such as a wooden boundary fence
- 600mm away from screening (e.g. trellis and foliage) that does not form part of the boundary.
If it is impossible to comply with these requirements, then a fire protection barrier with at least 30 minutes fire rating should be provided. A minimum separation distance of 100mm is required between the tank and fire rated barrier unless a larger distance is specified by the tank manufacturer.
In some situations, the oil storage tank can be sited inside a building such as a garage or outhouse. Installations of this type require the tank to be self-contained within a 60 minute fire rated chamber. Your OFTEC registered technician can advise further on this type of installation.
Don’t forget the support
The need to provide a suitable base and support for your oil tank is of paramount importance for reasons of both safety and environmental protection. The base should be:
- Adequate for the weight of the tank
- Non-combustible, imperforate and level
- Constructed of concrete, paving stones or stonework
- Large enough to extend 300mm beyond all sides of the tank.
If an oil storage tank is not adequately supported, the tank itself can be weakened leading to the eventual failure and escape of the stored fuel. During the life of an installation an oil storage tank base will need to provide continual structural support, even though ground conditions may alter from season to season and year to year.
Oil storage tank installations need to comply with regional Building Regulations. In England and Wales, OFTEC registered technicians can self certify their own work without involving Local Authority Building Control. But if you choose to use someone who isn’t registered with a ‘Competent Person’ scheme like OFTEC, then you will have to obtain a Building Control Notice and arrange for an inspection which can be costly and time consuming. Similar rules apply in Scotland where you may need to apply for a warrant. Your OFTEC registered technician can advise you on this.