Let's assume that we're spraying a living room wall with a sliding glass door six feet wide and seven feet tall. The slider is set in a drywall pocket, six inches deep. The drywall pocket is a significant change in direction. If the wall is being sprayed, then the door must be masked or shielded. Therefore, the wasted overlap of the paint onto the shield or masking paper must also be considered.
Productivity decreases when repetition is interrupted.
Supply costs, i.e., masking paper, tape, and shields, increase when surfaces must be protected. An average sprayer, working alone, can spray at least 50 gallons of wall paint a day doing production work. This paint would cover about 10,000 SF of two-coat work. If painting around a slider saves 22 SF of labor, then approximately one minute of spraying time has been saved. So, painting around a slider costs 15 more minutes in labor costs and reduces material costs by a dollar.