Single-Wall vs. Double-Wall Fuel Tanks: What’s the Difference?

Double-walled tanks for fuel storage are in perpetually growing demand at industries, municipalities, hospitals, and large commercial complexes that use diesel generators. To put the demand in perspective, the state of California saw a 1,400% rise in diesel generators in 2021. According to another report, the diesel generator market should surpass US$ 35,208 mn by 2030. That is a CAGR of 7.4% from 2021 when the market was at US$ 18,596.

Businesses that operate these generators require large frac tanks. Therefore, the demand for single-walled and double-walled tanks for fuel storage is set to rise in the future as well. Diesel is not as flammable as gasoline and is safe to store above ground.

In this blog, we will understand the differences between single-wall and double-wall fuel tanks, the advantages, and the factors that should dictate your choice.

The Main Difference Between Single-Wall and Double-Wall Fuel Storage Tanks

Fuel is a hazardous liquid. Spills can damage the environment, pollute water sources, and put your business at risk of litigation. The Spill Prevention, Control, and Countermeasure (SPCC) regulations under the Environmental Protection Agency (EPA) define guidelines to reduce the risk of environmental pollution due to oil spills.

This brings us to the differences between single-wall and double-wall fuel tanks.

Single-Wall fuel tanks Double-Wall fuel tanks
They are built with one layer of metal sheet. They contain two layers of metal sheet with a containment layer in between.
They require an epoxy-coated concrete secondary-containment structure to stop leaking oil. They already have an additional metal layer and do not need secondary containment.
These do not meet the EPA SPCC regulations without secondary containment. They are recommended by the EPA SPCC regulations.

How to Determine Whether a Tank is Double-Walled

There are a few ways to tell visually if the tank is single-walled or double-walled.

  1. Double-wall tanks are slightly larger than single-wall fuel tanks with the same storage capacity. This is due to the additional containment layer.
  2. Double-wall fuel tanks have a vacuum gauge to monitor the vacuum between the inner and outer layers. The gauge also signals the failure of the inner layer.
  3. Due to secondary containment requirements, single-wall fuel tanks feature an epoxy-coated concrete structure built separately at the site. If you are looking at one, the tank has a single wall.

Advantages of Single-Wall Fuel Tanks

Frac tanks have numerous industrial applications and come in different sizes. Single-wall fuel tanks are less expensive than double-walled tanks. If you already have an epoxy-coated concrete structure, you can go for the single-wall tanks and still meet the EPA SPCC regulations at almost one-third the cost of double-wall tanks.

Advantages of Double-Wall Fuel Tanks

Double-wall tanks have the following advantages –

  1. Double-wall fuel tanks already meet the EPA SPCC regulations.
  2. You don’t need to spend extra time and money building a concrete structure.
  3. The outer layer protects the inner one from rain, snow, sleet, and any other weather conditions that can cause damage. This avoids leaks due to rust and extends the life of the tank. In a single-wall fuel tank, it could be days before someone notices a leak.

View the Aboveground Storage Tank (AST) federal requirements.

Why Do Fuel Tanks Need a Double Wall?

All hazardous liquids, including diesel fuel, transformer oil, and heating oil, could leak and cause major environmental damage. Double-wall fuel tanks provide secondary containment features without additional construction on-site.

However, not all fuel tanks have a double wall. At Ironclad Environmental Solutions, you can get 16,380-gallon and 7,048-gallon mini double-wall tanks for environmentally sensitive areas such as forests, rivers, lakes, and high-density urban areas.

Single-Wall vs. Double-Wall — Which Should I Get?

Diesel or petroleum storage requires a double-walled fuel tank for the following reasons –

  1. Built-in spill containment solution
  2. Follows EPA SPCC regulations
  3. Greater resistance to weather and protection against rust

You should go for a single-wall fuel storage tank only if you are on a tight budget or already have an epoxy-coated concrete containment at your site.

Choose Ironclad Environmental Solutions Available in Your City

Ironclad Environmental Solutions offers storage solutions within 300 miles of any service location across the US. Some locations we serve on the east coast are New York, Florida, and Maryland. On the west coast, we serve California, Washington State, and more. View the full list of locations we are available in the US.


The double-wall fuel storage tank has significant advantages over the single-wall fuel tank. It reduces the overhead of building a concrete containment and makes your site compliant with the EPA SPCC regulations off the bat.

To meet the growing demand for fuel storage in the US, a wise choice is the double-wall fuel storage tank.

Ironclad Environmental Solutions works 24/7/365 to offer industry-leading storage and containment solutions in the US. We follow a culture of safety and comply with OSHA and DOT guidelines. To get a free consultation on a double-wall storage tank, contact us or write to us.


1.  Does a double-wall tank count as secondary containment?

      • The double-wall tanks have a built-in secondary containment compartment that is vacuum sealed. It protects the liquid from leaking and does not require an additional concrete containment space.

2.  Do fuel tanks need to be double-walled?

      • Not necessarily. But if you use a double-wall tank, you will automatically meet the EPA SPCC requirements. It will save you from salvaging the damage caused due to leaks and any litigation. To use a single-wall fuel tank, you will need to build an epoxy-coated concrete containment space.

3.  How long do double-walled oil tanks last?

      • The outer wall of a double-wall oil tank protects the inner layer from snow, rain, sleet, and other weather conditions that cause rust, and makes the tank last longer. With proper maintenance, double-wall tanks can last as long as 50 years.