I've got these to put on the door, and left a 3mm gap at the bottom so the brushes just touch the floor. However, whether they are poorly made or its
just debris on the floor, the brushes have been coming away in a few days. the brushes are 4mm, so theres a 1mm contact with the flooring.
Does the 3mm gap need to include the brush, and why are the brushes coming off so quickly - the plastic is still on the door, just the brush itself coming off.