Storage containers are built with 12-or-14 gauge corrugated steel sides, roofs, and doors. The floors of the container are made from marine-grade plywood that, despite being just one inch thick, is able to withstand up to 16,000 pounds of pressure per 100 square feet. Manufacturers weld containers together with an elastic sealing compounds so that they are completely airtight and watertight. The heavy-duty construction of the containers meets ISO construction standards and models of these containers are made to be fireproof and weather resistant as standard. In order to offer protection against vandalism and theft, the containers are made with swing-out doors that have galvanized interior locking bars, similar to those found in bank vaults. Cam rods and padlock hasps are also used to secure units and protect the contents of the unit after hours. While the average commercial storage container is made from steel, there are some other portable storage solutions including ones made from fiberglass and wood. While these are handy for personal use, they could lack the durability and reliability needed for commercial use.