They should come out looking good if you can take them down, and clean them on the ground. the best advice I can give is make sure you can brush both sides of the fabric with the solution without allowing it to dry before you can rinse. I use a “truck washing brush” I get from my local janitorial supply.
Myself, On both solar & regular screens I use a five gallon bucket with a few drips of Dawn. I lay the screen flat either on a driveway or any hard surface. I take a bi-level deck brush attached to a pole. I use a shorter extention pole so if it is a big screen I can adjust it for a longer reach. I wet the screens first then dip my brush in the bucket, scrub the screen on one side, flip it, scrub that side, lean it up againsts a fence or the house and rinse then real good. Let it dry some while doing the other screens. When I am ready to reinstall I wipe the screen frame.
That gives you what I use and the method. It’s the easiest, most thorough & economical way that I have found.
I would also recommend Tide with Bleach Alternative. I take the screens off, number them and stack them up. I then fill a bucket with solution. Use you garden hose to knock the chunks off, then scrub both sides with brush and solution. Rinse off twice with hose again. Stack to dry. Then clean the glass. By the time you are done with the glass, your screens will be dry and ready to replace.
Not to beat it to death, but I cleaned some screens just like these the other day. They were very dirty and Tide did wonders. I’ve been using a little more tide( about a cap full for 3 gallons) than usual lately, with great results. Letting it dwell for about 30-60 sec seems like it makes the shine of the screen come out more evenly. If your using a scrubber, I like the monsoon or microfiber sleeve.( never the porcupine!) Also, my hogshair brush works great too. Btw, I scrub them on a large, rectangle card table.
I seem to remember the spike or shovel advertised either in AWC mag or on the net. Just thinking here - would comressed air not do the job with a pole? You could perhaps cut it in segments or somehow lift the ice? I’m not familiar with your roof tiles so I may be way off here. Just a thought, probably a lot less hassle than adding heat to the equation?
Theres just something different bout the high desert. The dust is finer siltier .Why on hot sunny day with a little wind your covered in a thin layer of dust the, southwest’s finest in fact even before you break a sweat you can write WASH ME on your fore arm thru the dust! Now you mix in a little dry air you know what I’m talkin bout Scott well you mix in that low humidity and you have the just right conditions for a little static charge and you add that to one them thar solar screens with that fabric that has so much surface area and the tendency to be electrically charged with any friction what so ever… well then my friend you have the perfect storm the hardest screens to successfully clean this side of the RIo Grande. I searched for years to find the solution and I now have it thanks TO LANCE IN AZ great results thanks !!!