With surface-tension gutter guards, water clings to the rounded nose of the guard and flows into the gutter
, while leaves and other debris fall off over the edge.
As a result, water flows readily through the foam filter insert, into the gutter
valley and out the downspout to virtually eliminate overflows and the collection of stagnant water that can also attract breeding insects and feeding animals.
A diverter will help direct the water back into the gutter
where it belongs.
The lip on the guards relies on surface tension to draw the water down into the gutter
, while the solid covering deflects leaves and other debris that would otherwise drop in (photo above).
A gutter flashing or drip edge should direct water down into the gutter so it doesn't dribble backward into the soffit.
C) will effectively reduce the amount of debris that gets into the gutter and reduce cleaning.