TonsOfDirt breaks fill listings into six categories: inorganic fill dirt, organic topsoil, sand/gravel, rock, mulch/manure/compost, and demolition materials. These categories are broad and TonsOfDirt encourages listings to select the most appropriate and further describe the dirt in their comments.
Inorganic fill is dirt found underground, below the surface layer of topsoil, and contains little to no organic material or nutrients. May contain minor amounts of fieldstones, rocks, and roots. Inorganic fill is not useful for growing plants. The best use for inorganic fill dirt is landscaping, filling or levelling areas of land, building up yards, etc. Clean fill dirt is not very valuable compared to the other fill types on this site; it is the most common dirt available and is often disposed of as free fill. Be sure that any dirt you receive or post on TonsOfDirt is clean and free of contaminants. It is often illegal to transport contaminated fill.
Topsoil, best used for gardens or minor landscaping, is full of organic materials and will better support plant growth. While not as nutrient rich as potting soil, topsoil has much more nutrient content than inorganic fill. Topsoil should be layered over top of exposed inorganic fill if you want to grow plants in that area. Levelling your lawn would be best done with topsoil. Gardeners and landscapers will want to look for any topsoil resources available. Combined with manure or mulches this garden soil will make excellent growing.
While not as abundant as other fill types, sands and gravels are still available. Typically taken from blast sites or other development sites, sand, gravel, and other rocks may be mixed together or mixed in with dirt due to the excavation. Make sure you preview the material to make sure that the mixture is acceptable. Straight sand or straight gravel may also be available or may be available at a cost from a gravel mart or other commercial seller. Fieldstones depending on their size may belong to either this category or the Rock category. Landscapers and decorative gardeners may be interested in fieldstones or river rock for the aesthetic appeal.
Typically used to describe large rocks larger than a football. These rocks are often the result of blasting or deep excavation. Large boulders may be used in building rock walls or other landscaping features. As with sand and gravel these rocks sometimes come covered in dirt but are typically just the rocks themselves with little to no dirt mixed in. Make sure you have the equipment to move these rocks should you get a bunch delivered.
Good for fertilizer or moisture protection for your garden, this category is very highly organic. Mulch is plant cuttings, woodchips, and other shredded material used to protect moisture levels in your garden soil. Manures have many different benefits and uses depending on the source animal; some manure can be significantly higher in acidity than others. You may want to make sure that the manure isn't smelly if you live in a residential area. Compost can be just about any other organic materials that have been aerated and decomposed into nutrient-rich soil.
Demolition material can refer to any number of different materials or mixtures. Examples of demolition materials are crushed concrete, bricks, and asphalt. Other demolition materials are crushed glass, broken lumber, etc. Some materials in this category may not be outright hazardous but certainly require caution. Glass is the perfect example, and nails or screws in broken lumber is another. Definitely inspect the material before accepting delivery.