Portable Storage Containers: What to Inspect Before You Load Yours

Spend five minutes on the container before you put anything in it. Check the roof from inside with the doors shut, run your hand along the door gaskets, look at the floor for soft spots and stains, and confirm the doors close and lock without fighting you. That's the whole inspection, and it's worth doing whoever you rent from.

I say that as someone who rents these out. A good provider will have already checked, but you're the one whose furniture is going in it, and a problem is trivially fixable on delivery day and a real headache six weeks later.

The five-minute inspection

1. Stand inside and close the doors

This is the single best test and it takes thirty seconds. Step in, pull the doors to, and look up.

You should see essentially no daylight. A pinhole of light at the roof line or a corner means water gets in there. Look along the roof panels, the seams where the roof meets the walls, and all four corners.

Then look at the door frame from inside with the doors closed. Thin outlines of light around the perimeter of the doors are normal on some containers because of how the gaskets sit, but you shouldn't see gaps.

2. The door gaskets

Run your hand along the rubber seals on both doors. You're feeling for:

• Cracked or hardened rubber. Old gaskets go stiff and stop sealing.
• Sections that have pulled away from the channel.
• Torn or missing pieces, usually at the bottom corners where things get dragged past.

Doors are where water gets in, not the roof. A good seal here matters more than anything else on the box.

3. The floor

Walk the whole floor and put weight on it. What you're looking for:

• Soft or springy spots. Means moisture damage underneath. Don't put a piano or a tool chest there.
• Dark stains. Could be old oil, could be a past leak. Ask.
• Splinters or lifted edges that will snag furniture and boxes.
• Grit and debris. A container should be swept out. If it isn't, ask for a broom, because grit under a dresser scratches it every time the box moves.

If the floor is decent but you're storing something valuable, a few dollars of cardboard or a couple of moving blankets down first solves the whole issue.

4. The doors and the hardware

Open and close both doors fully before the driver leaves.

• They should swing without you shouldering them.
• The locking bars should rotate and seat cleanly in the cams.
• The handles should latch.
• Hinges shouldn't be seized.

A container set down out of level will have doors that bind. That's the most common cause and it's fixable in two minutes on delivery day — the driver shims it or repositions. Six weeks later, with a full container, it's a much bigger job. So test the doors while the truck is still there.

5. The lockbox

Most decent containers have a steel lockbox welded over the locking bar that shrouds a padlock so it can't be reached with bolt cutters. Check that yours has one and that your lock fits inside it.

That informs which lock to buy. A shrouded lockbox wants a short-shackle disc or puck lock, not a tall padlock that won't fit. We go through the options in the best lock for a storage container.

What good steel actually looks like

Surface rust on the exterior is cosmetic and normal on any container that lives outdoors in Southern California. It doesn't mean anything.

What matters:

• Corrugated walls with no punctures. Dents are fine — the corrugation is what gives the wall its strength, and a dented panel is still sealed.
• Corner castings intact. These are the heavy steel blocks at each corner that everything gets lifted and secured by.
• No rust-through. Bubbling paint with soft metal underneath is different from a brown patch. Push on anything that looks questionable.
• Roof panels not pooling. Container roofs are slightly ribbed and shed water. A dented roof that holds a puddle will eventually rust through from the top.

Where it gets placed matters as much as the box

Half the problems people have with a container aren't the container. They're the ground under it.

• Level. Out of level means doors that bind and, over months, a load that leans.
• Firm. Concrete or asphalt is ideal. Packed gravel is fine. Soft dirt and fresh lawn will let one corner settle after the first rain, and then you have an out-of-level container full of your furniture.
• Drainage. Don't put it in the low spot of the yard where water pools.
• Not directly under a big tree. Sap, leaves in the door channels, and limbs during a wind event.

Our drivers use a remote-controlled placement system, so the container goes exactly where you want it rather than wherever the truck can reach. If your driveway looks marginal, send a photo before you book — details in tight driveway delivery in LA.

Managing moisture inside

Steel is cold, and cold steel plus warm humid air equals condensation on the inside of the roof. It's the most common complaint people have about any container anywhere, and it's mostly preventable.

• Load everything dry. One damp rug, one wet tarp, one just-washed patio cushion will humidify the entire box. This is the biggest single factor.
• Desiccant. Hanging moisture absorbers from the hardware store, two or three for a large container, swapped every couple of months.
• Get things off the deck. Pallets, 2x4s, or a bottom layer of sacrificial boxes.
• Don't seal a mattress or upholstery in plastic unless it's fully dry. See how to wrap a mattress.
• Leave a little air space between stacks and the walls rather than packing dead tight against cold steel.

If you're near the coast — the South Bay, Long Beach, coastal Orange County — take the desiccant seriously. Inland, less so.

Photograph it on day one

Before you load anything: walk around the outside and shoot the four sides, then shoot the inside floor and the roof. Takes two minutes.

It documents the condition you received it in, and if there's ever a question about a dent or a stain, you have the answer. Do the same when you finish loading — a photo of a full container is also the only inventory most people will ever have, and it's exactly what an insurer wants. More in portable storage container insurance.

What to ask on the phone

1. What condition is the container in — and can I decline it if the floor or seals are bad?
2. Is there a lockbox, and what lock do you recommend for it?
3. Will the driver level it if the doors bind?
4. Can it be repositioned if I picked the wrong spot?

Any provider worth using answers all four without hesitating. Ours is: yes, decline it and we'll bring another; short-shackle disc lock; yes; and yes, though it's easier before it's full.

You can see every size we run on the mobile storage rentals page, and the size guide is in what fits in each container size.