There's a new development near me where the builder seems to have used badly designed frames.
Well badly designed for wfp cleaning.
The openers drain onto the glass below for hours after you have left causing very noticeable runs.
The drain hole is above the rubber seal which has a gap to let the drain water out, so the water has to run along the rubber to drain so then gathers dirt from the seal. (hope this makes sense hard to explain)
It must be the pressure of brushing the glass that causes the frames to fill with water as they don't seem
to leaves runs when it rains.
Have tried brushing using as little force as possible but no joy.
God help us if these frame types become the norm.