Next check the slope of the guttering runs.
Water spilling over gutter.
If your gutters are clog free and water is still spilling over onto the ground then your gutters may be improperly positioned.
Holes through the splash guard and the gutter.
If the gutter is tilting away from your house it could be causing an overflow particularly during heavy storms.
There are two sizes of this drain tile 3 and 4.
In roof valleys rain water will travel faster especially during a heavy storm or if the gutters are already full and the water will skip over the gutter and right onto whatever or whomever is unlucky enough to be beneath it.
This creates a problem where water backs up and creates a funnel effect effectively making it so that water cannot get down the downspout fast enough so it backs up in the downspout and spills over the gutter.
Thankfully there s a fix for this and it s called a gutter splash guard.
If you have any type of gutter guard or gutter cover system you ll usually have issues with gutter overflow.
Drill rivet holes for the gutter splash guard.
You can find these precut gutter splash guards about 3 in brown and white aluminum at a home center but you could easily make your own out of aluminum or sheet metal and spray paint them to match your gutters.
The pitch of gutter heading towards a downspout can also cause overflow if it s too steep.
Use caution when companies suggest a larger gutter.