How much do you actually need
Transporting soil, compost and mulch almost always goes wrong on weight, not on space in the vehicle. A gardener works out the area of a flower bed, buys the material and finds out at the collection point that the quantity ordered weighs more than they imagined. An hour spent with a calculator before you buy saves a second trip and an overloaded vehicle.
Work out the volume from the area and the layer thickness
Multiply the area of the bed by the thickness of the layer you want to spread. Ten square metres and five centimetres of compost makes half a cubic metre. For mulch, you allow for a thicker layer, because it's meant to prevent drying out and weeds. Add a tenth to the result as a reserve for topping up.
Weight is a different matter
A cubic metre of moist soil weighs over a tonne. The payload of vans differs by model, usually 1 100 to 1 450 kg, so one cubic metre of topsoil is the ceiling for one trip. Potting composts and peat mixes are much lighter, and mulching bark is light but takes up a lot of space. We have an overview of the vehicles in our fleet.
Bagged or loose
Bagged goods belong in a box van. You load the bags, line them up and, above all, carry them out again. Loose soil has to be shovelled out, and that's a job for a long afternoon. If you're buying a larger quantity loose, have it delivered by a tipper truck and use the van for the rest of your garden shopping.
Buy when it's dry
Material stored outside soaks up water and gains weight. Bags that have been lying in the rain for a week are noticeably heavier than those from a dry warehouse. If you're planning to buy up to the maximum payload, keep an eye on the weather and on where the seller stores the goods.
Know the difference between soil, compost and mulch
Each of these materials has a different function and is bought in a different quantity. Topsoil is used for filling and levelling the ground, potting compost goes into plantings and window boxes, and garden compost is worked into the soil as nourishment. Mulching bark or wood chips are spread on the surface at the very end. If you get this clear in advance, you won't be buying expensive potting compost where ordinary soil would do.
Ask how the goods are packed
The packaging determines how demanding the loading will be. You can only move bulk bags with the help of a trolley, and you won't get them into the garden on your own. Smaller bags can be carried by hand, but there are many more of them and both loading and unloading take longer.