Home gardening and large-scale landscaping projects often require substantial amounts of topsoil to establish new beds or grade uneven areas. Delivery typically involves a dump truck rather than small bags from a garden center. Understanding how much topsoil a large vehicle can actually transport is a common source of confusion for customers placing bulk orders. This article clarifies the industry measurements and the capacities of the different trucks used to deliver material.
Understanding the Cubic Yard
The standard unit for measuring bulk materials like crushed stone, mulch, and topsoil is the cubic yard (CY). This volumetric measurement represents a cube that is three feet wide, three feet long, and three feet high. Selling topsoil by volume rather than weight helps to standardize pricing across different materials, regardless of their moisture content or density.
Standard Capacities of Common Dump Trucks
The size of a topsoil delivery is directly determined by the type of dump truck employed, based on its axle configuration and carrying ability.
Single-Axle Trucks
For smaller residential projects, the single-axle dump truck is frequently used due to its maneuverability on driveways and residential streets. These trucks typically hold a modest volume, usually ranging from 3 to 6 cubic yards.
Tandem-Axle Trucks
Moving up in capacity, the tandem-axle truck is the standard for most residential and medium-sized commercial deliveries. This configuration features two rear axles, which distributes the weight more effectively, allowing for a larger payload. A standard tandem-axle dump truck transports between 10 and 15 cubic yards of material.
Tri-Axle and Quad-Axle Trucks
When projects demand greater volumes, the tri-axle or quad-axle dump trucks are preferred. The addition of a third or fourth axle increases the truck’s Gross Vehicle Weight Rating, permitting a larger load of heavy topsoil. These heavy-duty vehicles can deliver between 18 and 22 cubic yards, providing a cost-effective solution for large-scale landscaping or construction sites.
Tractor-Trailer End Dumps
For substantial commercial operations, the tractor-trailer end dump combination is utilized. This setup involves a semi-tractor pulling a large trailer that tilts up to empty the contents. These massive trailers are rated to haul the largest quantities of topsoil, with capacities ranging from 25 cubic yards up to 40 cubic yards.
Why Load Sizes Can Vary
Although a truck’s bed may be large enough to hold a specific number of cubic yards, the actual delivered volume of topsoil can be less than the theoretical maximum. The primary limiting factor is the truck’s maximum legal weight, which is governed by its Gross Vehicle Weight Rating (GVWR). Topsoil is a dense material, and a truck will reach its weight limit before its volume limit, a situation known as “weighing out.”
The density of the material is directly influenced by its moisture content. Topsoil that is saturated will be heavier per cubic yard than dry, screened topsoil. A truck might carry 15 cubic yards of dry material, but that same truck might only be able to transport 12 cubic yards of wet soil before exceeding its weight capacity.
Material compaction is another variable. Safety regulations and the need to prevent spillage on public roads also play a role. Regulations prevent material from exceeding the height of the sideboard extensions. These practical and legal constraints mean the cubic yard capacity figures are often a maximum potential, subject to reduction based on the material’s current state.
How to Calculate the Topsoil You Need
Calculating the amount of topsoil needed for a project prevents over-ordering and delays from under-ordering. The necessary volume is determined by measuring the length and width of the area and the desired depth.
The calculation involves multiplying the length by the width by the depth to get the total cubic feet. That total is then divided by 27, which is the number of cubic feet in one cubic yard. For example, a 10-foot by 10-foot area requiring 4 inches of topsoil would involve converting the 4 inches to 0.33 feet, resulting in (10 x 10 x 0.33) / 27, which equals approximately 1.22 cubic yards.
It is advisable to round the final calculation up to the nearest half or whole yard, as measurements on the ground are rarely perfect. Order an additional 5 to 10 percent more than the calculated amount to account for settling and compaction of the soil after it is spread.