Robert F,
Generally when your pushing good snow, the skids won't leave any scratches or marks on your concrete. Set the skids so there is a .125-.25 inch gap between the blade edge and the concrete. This will prevent wearing down your blade edge so fast and it will allow a small amount of snow under the blade. This thin layer of snow will also act as a lubricant barrier for the skid and prevent it from leaving scratches. The only time I've had the blade skids scratch the sidewalk is when you run out of snow, like between drifts. Then I lift the blade up until I get back in snow. Hope this helps.
Generally when your pushing good snow, the skids won't leave any scratches or marks on your concrete. Set the skids so there is a .125-.25 inch gap between the blade edge and the concrete. This will prevent wearing down your blade edge so fast and it will allow a small amount of snow under the blade. This thin layer of snow will also act as a lubricant barrier for the skid and prevent it from leaving scratches. The only time I've had the blade skids scratch the sidewalk is when you run out of snow, like between drifts. Then I lift the blade up until I get back in snow. Hope this helps.