This is where discolored streaking appears on the front side of a gutter due to rainwater dripping over the sides. This can happen whether or not you have a gutter guard installed on your gutter. However, this tiger striping can be more prevalent on the front of a gutter if a gutter guard is installed. Ironically, you are more apt to notice tiger striping once you install gutter guards since you may not have been assessing your gutters in the same way before. If you are noticing any tiger striping with gutter guards installed, then there are a few things you can do to reduce it from continuing to occur or eliminate it altogether:

• Clean off any debris that may be sitting on top of the gutter guards, which typically be done from the ground using The Gutter Guard Brush on the end of any standard extension pole.
• Make sure the gutter guards are installed correctly. Sometimes, a minor adjustment to the guards is required to eliminate rainwater running over the front of the gutter. Refer to the page of the Install Guide that addresses “removing the gap and trough depth.”
• If a high volume of rainwater flows down the roof valley(s), leading to an inside miter, and/or from an upper downspout onto the roof surface, leading to a straight run of a gutter, then you may want to consider installing a perforated rainwater diverter on the roof side of the gutter.

The streaking can be removed with Simple Green or another non-abrasive (non-alcoholic) cleaning solution.”