A roof drainage system, comprising - at least two gutter brackets, each gutter bracket comprising - a back portion for attachment the gutter bracket to a building, - an intermediate portion extending outward form the back portion for receiving a gutter element, and - an outer portion extending from the intermediate portion, wherein - the outer portion comprises an adjustable adjustment member, comprising a flashing attachment means for receiving a flashing element, wherein - the height / vertical position of the flashing attachment means is arranged to be adjustable in an adjustment range in relation to the intermediate portion - at least one gutter element arranged on said gutter brackets, and - at least one flashing element attached to the adjustment members of said gutter brackets, wherein - one of the gutter brackets is arranged higher than another of the gutter brackets so that a desired gutter slope diverging from horizontal level is provided, and - the adjustment members of said gutter brackets are adjusted such that said flashing element is in horizontal level, characterized in that the flashing element comprises -- a facade element and -- a base element arrangeable between the gutter brackets and the facade element, wherein - the base element comprises an attachment means for matching to said flashing attachment means of said at least two gutter brackets, and wherein - the facade element is attachable to the base element, and wherein the attachment means are arranged in at least one groove that extends in lengthwise direction on outer surface of the base element. - at least two gutter brackets, each gutter bracket comprising - a back portion for attachment the gutter bracket to a building, - an intermediate portion extending outward form the back portion for receiving a gutter element, and - an outer portion extending from the intermediate portion, wherein - the outer portion comprises an adjustable adjustment member, comprising a flashing attachment means for receiving a flashing element, wherein - the height / vertical position of the flashing attachment means is arranged to be adjustable in an adjustment range in relation to the intermediate portion - at least one gutter element arranged on said gutter brackets, and - at least one flashing element attached to the adjustment members of said gutter brackets, wherein - one of the gutter brackets is arranged higher than another of the gutter brackets so that a desired gutter slope diverging from horizontal level is provided, and - the adjustment members of said gutter brackets are adjusted such that said flashing element is in horizontal level, characterized in that the flashing element comprises -- a facade element and -- a base element arrangeable between the gutter brackets and the facade element, wherein -- a facade element and -- a base element arrangeable between the gutter brackets and the facade element, wherein - the base element comprises an attachment means for matching to said flashing attachment means of said at least two gutter brackets, and wherein - the facade element is attachable to the base element, and wherein the attachment means are arranged in at least one groove that extends in lengthwise direction on outer surface of the base element.