should be no mark up for materials, but depending on how the contractor does their estimates, they do add a markup of 20 to 30 percent. I do materials at cost, and labor is a set fee per day.
Every company is different on their markups. It depends on a lot of factors and overhead. We sell specific materials at cost and my overhead/profit is already figured into my general conditions. But in general I would say anywhere between 15-30%.
30% is the average. It can vary depending on the size of the overall project.