With different washes doing different volumes we have different labor structures. We have a minimum of 2 employees and at some sites 3 for many hours. We are close to minimum wage but try to stay 10% or so above it as a base hourly wage. We also offer incentives/growth which quickly raise most employees to 20-40% over minimum.
I always recommend at least 2 employees working at all times at a minimum. This provides a higher minimum standard for service and safety. If you have higher volume or sell memberships plan on a 3rd for peak hours and days.
Pay is difficult. I would consider how many people are on, how many jobs they do and the conditions they do them in. If you are a busier express that sells unlimited realize that you need a more skilled employee to be successful and will have to pay for that. It is also hard because the management structure can determine this as well. The less you pay the more no shows and turnover you will get. Do you have a system to deal with that and stay open?
Remember, you get what you pay for. Your needs and the job market also may change unexpected. Be ready to have payroll go up at moments notice if you can’t fill positions for a prolonged period