Direct costs stop if the job stops. They are different from overhead, which the company pays whether it has that job or not.
Example: for a flooring job, direct costs include the flooring, adhesive and freight. They also include burdened installer wages and the rented floor grinder.
List every direct cost before you add overhead and profit. Estimators often miss freight, small tools, permits, travel and cleanup. Some companies also count job-specific supervision as a direct cost. Use one rule every time, so you can compare one job to the next.