An ALD coating method to provide a coating surface on a substrate is provided. The ALD coating method comprises: providing a deposition heading including a unit cell having a first precursor nozzle assembly and a second precursor nozzle assembly; emitting a first precursor from the first precursor nozzle assembly into chamber under atmospheric conditions in a direction substantially normal to the coating surface; emitting a second precursor from the first precursor nozzle assembly into chamber under atmospheric conditions in a direction substantially normal to the coating surface; removing moving the substrate under the deposition head such that the first precursor is directed onto a first area of the coating surface prior to the second precursor being directed onto the first area of the coating surface.