Method for joining a first component to a second component by means of one-sided resistance spot welding, comprising: - producing a spacing between the first component and the second component in the region of a resistance spot of the resistance spot welding by means of a spacer device, - pressing a welding electrode onto the region of the resistance spot from one side, and - bringing the components (7, 9) closer together for the local production of an electrically conductive butt contact between the components (7, 9), wherein the components (7, 9) remain spaced apart, at least in some areas, adjacent to the resistance spot, - producing an electrically conductive butt contact between the second component and a dummy electrode of the resistance spot welding, - pressing the welding electrode onto the first component from one side and - producing an electric welding current from the dummy electrode via the second component, the resistance spot of the components (7, 9), the first component to the welding electrode to melt the resistance point of the components (7, 9), characterized in that in order to produce a concentration of the welding current between welding electrode and the region of the resistance spot, an insulating strip of the spacer device is inserted between the components (7, 9), wherein the insulating strip has at least one cut-out, wherein, during the resistance spot welding, the components (7,9) are brought closer to each other locally through the at least one cut-out in the region of the respective resistance spot, and the insulating action of the insulating strip surrounding the respective resistance spot is maintained. - producing a spacing between the first component and the second component in the region of a resistance spot of the resistance spot welding by means of a spacer device, - pressing a welding electrode onto the region of the resistance spot from one side, and - bringing the components (7, 9) closer together for the local production of an electrically conductive butt contact between the components (7, 9), wherein the components (7, 9) remain spaced apart, at least in some areas, adjacent to the resistance spot, - producing an electrically conductive butt contact between the second component and a dummy electrode of the resistance spot welding, - pressing the welding electrode onto the first component from one side and - producing an electric welding current from the dummy electrode via the second component, the resistance spot of the components (7, 9), the first component to the welding electrode to melt the resistance point of the components (7, 9), characterized in that in order to produce a concentration of the welding current between welding electrode and the region of the resistance spot, an insulating strip of the spacer device is inserted between the components (7, 9), wherein the insulating strip has at least one cut-out, wherein, during the resistance spot welding, the components (7,9) are brought closer to each other locally through the at least one cut-out in the region of the respective resistance spot, and the insulating action of the insulating strip surrounding the respective resistance spot is maintained.