Type of snow guard?

In 2008, a COOLR 26 g. standing seam metal roof was installed on our 24-year old second home, located in central Wisconsin. We're very happy with it in general, except in winter. When there's a heavy snowfall, it slides off the southwest-facing roof with 8:12 pitch and a 26 foot 'run' x 28 foot width area onto a wooden deck, completely obstructing exit from the sliding door on that side. On the northeast side of the house, sliding snow from a 5:12 pitch, 14 foot 'run' x 26 foot area blocks access to a double attached garage. (Other roof areas are also affected; all dimensions approximate.) What type of snow guard system would solve this problem? Do you have any other comments or suggestions? I have photos, if that would help.