26/02/2024

The Complete Oil Tank Base Guide

Once you’ve decided on your oil tank size, material and location, you must find the right base to suit your tank. Our complete oil tank base guide will outline the importance of the base, the different types you can choose from, and any regulations you must comply with.

Why do you need an oil tank base?

Oil tank bases are essential to the longevity and safety of your oil tank. Domestic oil tanks can hold between 650 and 3,500 litres of heating oil, combined with the weight of an empty oil tank, is very heavy. If placed on uneven or soft ground, such as oil or grass, can cause the tank to tip, fall or sink, causing damage to your tank as well as the pipelines. This can then contribute to an oil tank spill and therefore, environmental damage.

What are bases made of?

Oil tank bases can be made from various materials, which must be impermeable and non-combustible to prevent ground contamination in case there is a fire near the tank.
 

The oil tank base can be made from any of the following:

• Concrete (at least 100mm thick)
• Paving / concrete slabs (at least 50mm thick)
• Pre-cast concrete (at least 50mm thick)
• Pre-cast concrete slabs (at least 50mm thick)
• Stonework (at least 50mm thick)

Regulations for bases

As oil tanks have regulations, their bases must also follow a set of rules to ensure maximum safety, including the base’s location and base material.

• Base material

  As previously mentioned, oil tank bases can be made from various materials. Bases must therefore be:

  • A compact, hard, and level surface
  • Made from non-combustible materials
  • A minimum of 300mm from each side of the tank
  • At least 50mm thick minimum, though some materials must be thicker.

 

• Base location

  As oil tank bases have location regulations, the base you install must comply with the same rules. These criteria are as follows:

  • 8m away from non-fire-rated buildings, eaves, structures or boundaries
  • 1.8m away from the flue terminals of oil-fired appliances
  • 600mm away from foliage
  • 1.8m away from openings in fire-rated buildings

   

  If you are relocating or replacing an old oil tank, make sure that you double-check the regulations, in case your old base does not comply with the current regulations.

Base Installation

Once you have chosen your oil tank and are ready to install it, it is time to get your base laid and set, in preparation for your tank.

Bases should be installed by an accredited OFTEC technician or engineer to ensure they are in place properly. They will analyse your garden area, tank material and tank size to recommend the right base for you.

Tanks constructed from various materials often require different base installations.

• Steel Tanks

  Raising a steel oil tank on two or more pillars to keep the base clear of groundwater can help limit the effects of corrosion that may occur from being sat so close to the ground.

   

  For single-skin steel tanks, it is recommended to tilt the tank slightly towards the drain end to ensure proper drainage of rainwater from the top of the tank.

 

• Plastic Tanks

  Bunded plastic tanks can also be installed on pillars so that the bottom outlet is higher than the boiler inlet, allowing gravity to feed the fuel directly to the boiler. If you want to raise your tank, it will need a base that is sat on pillars, and on top of another concrete base.

   

  A bunded plastic tank may also be placed directly onto a regular ground-level non-combustible base. This is preferable if the location has limited room, or to make it easier to hide your oil tank.

Next Steps…

If you’re ready to get your base in preparation for your new oil tank installation then contact a member of our team on 01638 781710, or send an enquiry.