Adrian if the rainfall overwhelms the rear track/channel holes on the outside it track switches onto the inside I have three holes in mine, two in the rear out track and one in the inside at the lowest point at the front.
They seem to do the job.
Mmm, I wondered if there was some reason like this, my front screens are sealed at the track point, and can't see how it could get to the front. I'll do a watering can test.
