Container Floors—A Close-Up Look

Depending on location and season, heavy rain - or even snow  - can impact the delivery of shipping containers. Deliveries can be halted as a result of soaked, soft ground. That gets you thinking about what keeps shipping container floors dry and sturdy in different environments throughout the year. So whether your shipping container is used for storage, as a shed or any other purpose, a solid floor makes all the difference in keeping the contents of your shipping container safe inside. But what exactly goes into making container floors so reliable? Today we're going to explore that in more detail.

Inside a new 40’ and a new 20’ container.

Shipping Container Flooring Construction

Container flooring is made up of two basic parts—steel cross-members supporting the floor and a wood floor. This combination makes for a very strong and exceptionally solid floor for your shipping container.

A container turned on its side so you can see the cross-members spanning the width of the container. The floor is on top of the cross-members.

First, steel cross-members span the width of the container. They are spaced out about every 5-6". They are about 5" high. The cross-members then have a rail that encircles the cross-members. This framework of the flooring gives it strength. For reference, a 20' container weighs 5,000 pounds, but it can hold 62,000 pounds. That is more than what you are allowed to drive down a highway without a special permit.

Floor pulled up over a forklift pocket showing the cross-member

The underside of a container showing the cross-members and underside of the wood with the sealant put on the container floors

From there, marine-grade plywood is screwed into the steel cross-members. Marine-grade plywood is plywood that has been treated to make it more waterproof and insect-proof. Also, an additional coat is put on the bottom of the wood to create even more of a moisture barrier. This type of plywood is ¾ - 1" thick.

The metal section in the end of 40’ containers

40’ containers have an additional section to their floors. There is a metal plate in the non-door end of the container that reinforces the floor in that end of the container. That is because sometimes the containers are moved with certain types of trailers that bump into the floor and if the metal wasn’t there, that section of the floor would need constant repair. The metal makes the floor sturdier.

Find Out More About Container Construction 101

Long-Lasting and Low Maintenance Container Floors

The result is that you have a nice, strong floor for your shipping container that will stay dry even if moisture is under the container. However, if your flooring should wear out over time with frequent usage, it is also easy to replace. Simply unscrew the section that needs replacing (or even part of a section that needs replacing) and screw in a replacement piece.

Related: Insulating Containers - What Are Your Options? 

Although you may have to walk through the wet ground to get to your container in the spring and fall, you can count on it being nice and dry once you’re in there.

Have questions about container flooring or ready to find your perfect shipping container? Connect with our expert team today for all the details you need.

This is an updated blog that was originally published in 2020.

Super Cubes is a family-owned business located in Minneapolis, MN, that provides containers anywhere in the continental US. We offer personalized service for individuals and businesses, providing high-quality containers at competitive prices. With nationwide facilities, we can modify and deliver containers close to you. Contact our experienced team for your next container project.