No. GutterFilter® is preferred by Roofing Contractors. It has no damaging nails or screws and won’t void your roof warranty. It allows homeowners to re-shingle without destroying their gutter protection.
GutterFilter® only retains 10 to 15% of the water that passes through it, and that for only a short period before it dries - it’s much too porous to hold any water weight. When gutters sag or collapse, it’s usually from the weight of water and debris trapped because of clogging.
Neither actually. “Shingle grit” is too large to enter through GutterFilter®’s pores and just sits on top. It’s also extremely porous and does not affect drainage or performance in any way.