If you own a plastic oil tank, keeping it well maintained in addition to its associated systems will keep fuel efficiency high, which helps cut costs and reduce the risk of breakdowns. If your business or home stores fuel in a plastic tank, keeping it up to standard is crucial, because a damaged plastic oil tank is nonrepairable.

Read on to find out all there is to know on keeping your plastic oil tanks safe, including how to avoid environmental damage and costly replacements. With a few regular and simple checks now, you could save tens of thousands of pounds in the future.

How long do plastic oil tanks last?

A plastic tank is usually a green, moulded polyethylene container. It has around a 10-15-year lifespan, but many problems can occur along the way which can cause a hazardous leak or contamination within storage.

Plastic tanks are often cheaper than steel tanks which can often lead to the misconception that they are better value for money. But steel tanks have a much longer lifespan and are less prone to damage from the elements and environmental factors, which is why steel tanks are often the preferred choice over a longer period.

What could damage a plastic fuel tank?

When you consider the stress plastic fuel tanks undergo when exposed to the elements, it’s no surprise that they become susceptible to damage over time. But the good news is that unlike steel fuel tanks, if a plastic tank develops any problems, they will usually appear on the exterior which allows easy examination and quick but temporary rectification. When a plastic tank has become cracked or split, it’s time to invest in a replacement.

OFTEC have developed a number of regulations to ensure homeowners and businesses understand and are familiar with all of the associated risks. Click here for more information.

Some common plastic oil tank problems

Sun & UV exposure

Single skinned plastic fuel tanks positioned in direct sunlight can become whitened or discoloured, causing the plastic to expand and eventually lead to deformities in the tank, such as twisting and bowing.

Sun bleaching weakens its weight bearing pressure points. Over time, cracks will develop where fuel can escape and water can get into the tank, leading to fuel contamination, costly environmental damage and machinery and boiler breakdowns.

To avoid sun damage, we recommend that you keep your tank out of direct sunlight in a fenced surround or fitting an underground storage solution.

Incorrectly fitted base

An uneven base can put a plastic fuel tank under substantial pressure, especially when full. This can cause the plastic to stretch and will eventually split or crack the tank. To avoid damage and leaks, it’s important that your tank is installed properly by an OFTEC registered company, who will install the tank on a flat and level concrete base.

Cold weather

Freezing temperatures can cause plastic tanks to become brittle which can lead to lower protection against physical damage, cracks and splits. After a heavy snowfall, it’s important that you clear any snow on the top of your tank, as the extra weight could be placing strain on parts of the tank not designed to be weightbearing.

During the winter months, we suggest that you check your fuel levels every fortnight when completing a tank inspection to ensure your tank has not deteriorated in quality and that there are no unseen leaks.


It’s important to check the lids on your tank to ensure they are securely closed. This will help avoid rainwater ingress through the bund or inner storage tank.

Water within a fuel tank can lead to bacterial growth and sludge formation on its base which can clog fuel filters, lines and injectors. This will eventually prevent the fuel from flowing at all.

We supply and install a variety of both plastic and steel fuel tanks in a wide range of sizes. To find out more about our fuel storage solutions, get in touch today on 0330 123 3773.

How to recognise problems with your fuel tank

To maintain your tank correctly, it’s important to conduct regular visual checks in addition to an annual tank inspection by a registered OFTEC company. If you’re using an older single skinned fuel tank, it’s sensible to upgrade to a plastic bunded tank sooner rather than later to limit the risk of failure.

Common areas to check:

  • Shrubbery and vegetation – dieback could indicate that there’s a leak coming from your tank. It’s also important to keep vegetation cut back to enable easy access and to avoid water entering your tank
  • Base and supports of your tank – any cracks and subsidence can infer that your tank and its components have deteriorated and need replacing straight away
  • Visible pipework, valves and filters – look for signs of damp, paying particular attention to joints and connection points as this can indicate a leakage
  • The tank body – bulging, cracks, splits, whitening and deformation can all lead to an oil spill or contamination in the tank
  • Tank bunds – if your tank is located within a physical bund, it’s important to remove any debris and rubbish.

How to prevent your plastic fuel tank becoming damaged

Cleaning up fuel spills is problematic and can be extremely expensive. It’s against the law to cause pollution and you’ll have to take action to clean up any severe spills or leaks which may also void your insurance.

Plastic fuel tanks cannot be repaired once they’ve started to deteriorate. Checking your tank regularly so you can notice the signs of a fault early on is key to avoiding a spillage.

We also recommend ensuring that your tank is safely and securely located on your site to minimise the risk of accidentally damaging the tank during fuel delivery, or with your day to day operations.

In addition, purchasing a high-quality plastic bunded fuel tank is an excellent investment. Buying your tank from Speedy Fuels will help you avoid leaks, save wastage, reduce costs and offers a safe storage solution for your fuel management system, while protecting the environment.

My plastic tank is cracked, what do I do?

If the cracks in your tank are above the oil level, it’s vital that you contact a professional company to replace your tank before you refill. Our experienced engineers will identify and assess any damage and offer additional advice on remedial action, or if needed, replace your tank.

A quick, but temporary fix to keep the cracks covered is using a bar of soap to plug smaller cracks and splits. This will prevent water getting in your fuel and contaminating it, and also delay oil from escaping the tank and damaging the surrounding environment.

When purchasing your plastic fuel tank, make sure it’s from a reputable supplier. Our drivers always complete a safety check on your tank before dispensing your fuel during the delivery. If they notice any damage or have any concerns regarding your tank’s condition, they will decide whether the delivery is safe to complete or not.

If you suspect that your fuel tank has a leak, please call 0330 123 3773 at any time, on any day. Our emergency line is manned 24/7 so we can provide expert guidance on how to contain the spill and the next steps to take to minimise any environmental contamination.

Should you still choose to use a plastic oil tank?

A plastic oil tank is a sensible choice as it’s less prone to corrosion than a steel tank. It’s a legal requirement for domestic tanks and those storing over 3,500 litres to be bunded. This is especially beneficial in an environmentally sensitive location. A bunded tank is made up of an inner tank that stores the fuel and an outer tank which provides additional protection for the stored fuel against contamination, leaks and theft.

To check that your fuel storage solution is compliant, read our simplified fuel storage regulations guide.

Is your fuel tank protected from theft?

There are several measures that you can take to deter thieves, including:

  • Fitting a padlock and a “This tank is alarmed” sticker
  • Locate the tank out of sight of roads and walkways e.g. an underground tank
  • Fit security lights or CCTV cameras

Read our blog post on the 7 oil tank fittings you need to avoid a spillage for more information.

Are you safe from running out of fuel?

It’s every fuel user’s nightmare to run out of fuel as this can either leave homes off the grid out in the cold or cause a business’s operations to grind to a halt.

The simplest and most cost-effective way to avoid running dry is to install a tank telemetry monitoring gauge. This will allow you to monitor your fuel levels from either the comfort of your own home or while completing other jobs within your business.

If you find yourself running dangerously low on fuel, call us today on 0330 123 3773. Our emergency fuel line is manned 365 days a year and your emergency delivery could be with you in just a few hours.