The materials serve different purposes
A grading project often needs an underlying layer to establish elevation and a surface layer suited to the final use. Fill and topsoil should be selected for those roles rather than treated as interchangeable loads of dirt.
Fill establishes the underlying shape
Suitable fill can raise selected areas and provide material for transitions. Its suitability depends on the intended use and placement requirements. Material acceptable for a general landscape project may not meet specifications for structural work or a heavily loaded surface.
Topsoil supports the landscape finish
Topsoil is generally considered for the growing surface where vegetation will be established. It should not be assumed to provide the required structural base beneath a building or other engineered improvement. Plan its thickness before setting the underlying grade.
Neither material replaces a drainage plan
Even good material can be placed in a way that traps water. The finish needs a continuous slope, suitable transitions, and a workable outlet. Adding soil without considering those relationships may move the low spot to another part of the yard.
Check material and ground conditions
Roots, buried debris, weak ground, and moisture conditions can affect the work. Discuss how unsuitable material will be handled and what placement or testing requirements apply. A smooth-looking surface alone does not verify compaction or drainage performance.
Coordinate delivery with the finished elevation
Estimate material from measured work limits and elevation changes. Clarify delivery access, where loads will be placed, how the soil will be worked, and what final stabilization is included. The finish should preserve the planned drainage shape after the final surface layer is added.
See our six-photo drainage and grading guide and grading services by city.