What Size Gravel Pad for a Shipping Container? (And How Level It Needs to Be)

By Paul LeBlanc, owner, Van Blanc Ent. Inc., with Christian LeBlanc, second-generation operator. Brantford, Ontario.

Last updated: June 20, 2026

Reading Time: 8 minutes

What size gravel pad do you need for a shipping container?

A gravel pad for a shipping container should be about one foot larger than the container on every side, built from 4 to 8 inches of compacted angular crushed stone. A 20ft box wants a pad near 22ft by 10ft, and a 40ft box near 42ft by 10ft. The extra apron lets the corner castings land on firm stone.

A gravel pad for a shipping container should extend about one foot past the container footprint on all four sides, and one to two feet is better where you have the room. A standard 20ft container measures 19’10” by 8’0″ (6.06m by 2.44m) at the base, so a pad in the range of 22ft by 10ft covers it with margin. A 40ft container is 40’0″ by 8’0″ (12.19m by 2.44m), so plan for roughly 42ft by 10ft. The extra apron is not waste. It gives the corner castings firm stone to land on even if placement is an inch or two off, and it keeps the splash zone around the base on gravel instead of mud.

Match the pad to the box you are buying. If you are still deciding on a size, the range of containers we stock at the Brantford yard lays out the footprints side by side so you can size the gravel once and not redo it. A high-cube 40ft (9’6″ tall) has the same footprint as a standard 40ft, so the pad size does not change, only the overhead clearance does. If you are putting two containers side by side, leave at least a couple of feet of gravel between them so water sheds off both walls cleanly and a person can still walk the gap to inspect or paint.

How level does the ground need to be?

How level does the ground need to be for a shipping container? Level enough that the box does not twist. There is no published code number, but the practical target the trade works to is within about one inch across the full length and across the width. A shipping container is a rigid steel frame, and the doors only swing true when all four corners sit in the same plane. Drop one corner an inch or two and the frame racks slightly: the door leaves stop meeting, the locking bars bind, and a gasket that sealed in the yard now lets in light. The cleaner the doors start out, the more a level pad protects them, which is part of why buyers who want the tightest factory seal look at a fresh one-trip unit that has only made a single loaded voyage and then set it on a pad worth the effort.

This is why level matters more than pretty. You can place a container on a slope, but the pad under it has to bring the four corner points back into plane. Out past about an inch of difference corner to corner, you start fighting the doors. Small corrections are normal and easy: a steel shim or a pressure-treated block under a low corner, raised in fractions of an inch until the door gasket lines up all the way across the opening. Build the pad close, and you only ever need a shim, not a rebuild.

Which gravel should you use, and which should you avoid?

For a shipping container pad, use angular crushed stone, not rounded river rock. Crushed stone has broken faces that lock together under compaction and stay put; round pea gravel and river rock roll under load and never knit into a solid base. Gravel is not the only base buyers ask about, and how it stacks up against railroad ties or timber blocks is its own decision; the standard choice here is 3/4-inch (19mm) clear or crushed stone. In Ontario the equivalent road-base spec is Granular A under OPSS.PROV 1010, a crushed sand-and-stone blend with a minimum of 50% crushed particles and all of it passing the 26.5mm sieve. That is the same material that goes under driveways and roads across the province, and it is exactly what you want under steel.

A layer of geotextile fabric under the stone is cheap insurance. It separates the gravel from the native soil so the stone does not slowly sink and disappear into clay over a few wet seasons. On the heavy clay common around Brantford and across southwestern Ontario, the fabric is the difference between a pad that lasts and one that needs topping up every couple of years.

Here is how the common base materials compare for a stationary container that has to stay level through Ontario freeze-thaw:

Base material	Stays level under load	Drainage	Frost behaviour	Best for
3/4-inch angular crushed stone (Granular A)	Excellent, faces interlock	Excellent, water percolates through	Resists heave when compacted with fabric	The standard container pad
Pea gravel or river rock	Poor, rounded stone rolls under load	Good	Shifts with movement	Not recommended under containers
Bare soil or grass	Poor on clay, corners sink	Poor, holds water against the floor	Heaves badly	Short-term placement only
Concrete slab or footings	Excellent	Sheds water but can pool at edges	Stable below frost line	Permanent occupied conversions

How deep should the pad be, and how do you compact it?

Pad depth for a shipping container runs 4 to 8 inches of compacted crushed stone on firm subsoil, and up to about 12 inches on soft or clay-heavy ground where the base needs to spread the load further. The number that matters is not the loose depth, it is the compacted depth. Loose gravel ruts under a delivery truck and lets the corners settle unevenly later.

Lay the stone in lifts of roughly 4 inches and compact each lift before adding the next. A plate compactor with several passes per lift gives you a base dense enough that a heel barely marks it. The goal is simple to state and worth the rented compactor: a surface that holds a 45,000 lb truck without rutting and holds four loaded corner castings without settling. Loose stone fails both tests.

Why does the pad need a drainage crown?

A gravel pad needs a drainage crown so water sheds away from the steel floor instead of pooling under it. Build a slight crown or slope into the pad, about 1 to 2 percent, so rain runs off the apron and away from the container. A container floor is marine plywood on steel cross-members, and the cross-members are the part that rusts when they sit in standing water. Gravel drains, which is most of why gravel beats a bare dirt pad. Adding the crown finishes the job: rain hits the roof, runs off the walls onto the gravel apron, and sheds away rather than collecting under the steel.

This is also why the pad extends past the footprint. The one-foot apron is the splash and drainage zone. Water coming off the container walls lands on stone and percolates down, not into a muddy trench right against the base rails. Keep the surrounding grade falling away from the pad, not toward it, and the floor stays dry through Ontario winters.

Will the ground hold the truck that delivers the container?

Ground bearing is where the pad earns its keep on delivery day. A loaded tilt-deck rig with a container on the deck can weigh well over 45,000 lb, and most of that rides on the rear axle group while the box slides off. The ground does not get tested by the container. It gets tested by the truck, and firm dry stone passes that test while soft, wet, or grassy ground can swallow a wheel before the container ever lands.

Once the container is down, the load story changes. The box funnels its entire weight through four corner castings, each roughly six inches square. At maximum gross a 40ft container puts on the order of 210 lb per square foot through its footprint, concentrated at those four points. A compacted gravel pad spreads that and keeps the corners from punching in. On a Van Blanc delivery, the container lands at ground level straight off the tilt deck, so when access allows there is no crane and no extra lift cost. The pad and the approach are what make that clean drop possible.

How much access does the delivery truck need?

A perfect pad does nothing if the truck cannot reach it. A tilt-deck delivery needs a roughly straight pull-out behind the drop point so the container can slide off the deck onto the ground, and the room it takes is more than people expect: plan on about 75 to 100 feet of straight clearance for a 20ft container and 120 to 130 feet for a 40ft. The rig needs about 12 feet of width down the approach, and during the tilt-off the raised deck needs roughly 14 to 16 feet of overhead clearance, a bit more for a high-cube. Watch for low branches, hydro lines, eaves, and sign posts along the whole path, not just over the pad.

When site access cannot give the truck that straight run, a HIAB crane lift becomes the way in, setting the box over a fence or into a tight yard. That is real work we do across Ontario, and it is worth a quick conversation before you build the pad so the pad ends up where the truck or the crane can actually reach. For the full picture on grading, frost, and anchoring beyond the pad itself, our deeper walkthrough on getting your site ready for a container, from frost heave to ground conditions covers what happens under and around the gravel.

Reach Van Blanc in Brantford

We have been supplying shipping containers across Ontario since 1995. Our warehouse is at 90 Morton Avenue E in Brantford, and we deliver right across the province. Tell us about your site and we will tell you straight whether your pad and access are ready for a tilt-deck drop or whether a crane lift is the smarter way in.

Van Blanc Ent. Inc. 90 Morton Ave E Unit 1B, Brantford, ON N3R 7J7. 519-754-6844

Building a pad this week? Call the Brantford yard before you order the stone, and we will help you size it to the exact box you are buying.

Related Reading

• Frost heave and anchoring beyond the pad
• Delivering onto dirt or a lawn
• Clearance the tilt deck needs
• Ties versus blocks versus stone