We build rental into the cost of the job - so it's considered a direct cost just like materials, company equipment or labor. Then overhead and profit is made on top of that. This covers all related costs to renting the equipment.
If it's a T & M job, we charge the customer an hourly rate, the materials plus mark up and company equipment (like dump truck, dingo, etc) at the daily rates. So we'll do the same with rental - and just put the piece of equipment in with the other equipment - we don't state that it's a rental - just charge for it.
Lawn Lad, Inc.