A support is provided, comprising a first bar with a first abutment element, a second bar with a second abutment element, and a guiding device by which the first bar is displaceably guided on the second bar. An actuating device which acts on the first bar and which comprises an actuating element is arranged on the second bar. A displacement of the first bar in a first direction of displacement can be initiated by actuation of the actuating element. The first direction of displacement is a direction of increase in distance between the first abutment element and the second abutment element. The actuating device comprises a blocking device which blocks a displacement of the first bar in relation to the second bar in a second direction of displacement, which is opposite the first direction of displacement, at least when no active releasing action occurs at the blocking device.

A clamp for installing a siding onto a building. The clamp comprises an upper frame having a nail for mounting the clamp onto the building and a lower frame having a top end pivotally connected to a lower end of the upper frame with a hook at an opposing end of the lower frame for holding a bottom of the siding. A spring is included biasing the lower frame with respect to the upper frame to angle the lower frame away from the building. In operation, the clamp is mounted onto the building and the hook is aligned to a position wherein the siding is to be installed, whereby the bottom of the siding may be placed on the hook and mounted onto the building.

A support is provided, comprising a first bar with a first abutment element, a second bar with a second abutment element, and a guiding device by which the first bar is displaceably guided on the second bar. An actuating device which acts on the first bar and which comprises an actuating element is arranged on the second bar. A displacement of the first bar in a first direction of displacement can be initiated by actuation of the actuating element. The first direction of displacement is a direction of increase in distance between the first abutment element and the second abutment element. The actuating device comprises a blocking device which blocks a displacement of the first bar in relation to the second bar in a second direction of displacement, which is opposite the first direction of displacement, at least when no active releasing action occurs at the blocking device.