Oil tank bunding: the rules behind that inner containment wall
A bunded tank is built with an outer skin surrounding the inner oil-holding tank, sized to contain the full tank capacity if the inner tank ever leaks or fails, preventing oil from reaching soil or watercourses.
The engineering behind oil tank bunding requirements
Building Regulations and the Oil Storage Regulations generally require bunding wherever a spill could reach a watercourse, drain, or where the tank sits within a certain distance of a building or boundary — which in practice covers the overwhelming majority of domestic installations. OFTEC-registered installers assess the specific site conditions rather than assuming a single blanket rule applies everywhere.
Things worth knowing about oil tank bunding requirements
- Bunding must hold at least 110% of the tank's total capacity
- Proximity to boundaries, drains and watercourses drives the requirement
- Most modern domestic oil tank replacements are fitted bunded by default
- Bund integrity should be checked visually at each service
- Leaked oil in a bund should be professionally removed, not just drained
Where we deal with this
Published business details
- Based at 24 Bristol Road, Radstock, BA3 3EE
- Telephone enquiries: 07516 118198
- Opening hours: Monday to Friday, 8:30am to 5:00pm
Book a visit for oil tank bunding requirements
The honest position: Bunding exists specifically to contain a worst-case spill, and getting the site assessment right at installation avoids problems with building control sign-off later.
Include the appliance make and model in your enquiry so the correct technical information can be checked.
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Services that cover this
Questions we get asked
- Is my existing single-skin tank illegal?
- Older single-skin tanks already installed are not automatically illegal, but any replacement will almost always need to be bunded under current rules.
- Can I install a bunded tank myself?
- Installation should be carried out or signed off by an OFTEC-registered technician to ensure it meets building regulations and insurance requirements.
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