In 14 yrs of trad work, when it came to conservatory roofs, i used a 3 section extension unger pole with a sill brush or flocked brush head. Similar to brush n poles to clean caravans or cars with. Squirty in a large filled unger oblong bucket and hosepipe to rinse down and squeegee bk on pole to blade of. Latterpart depending on roof material. Always did a good job and still do even tho on wfp now. Did a conservatory roof clean yesterday, same method but used my wfp n pure water to rinse and fish off, as pictures show.
Personally i wouldnt advice in investing in such equipment unless you are going down line of wfp on windows. Then if you are and depending the type of work do. I wouldnt mess around with backpacks or trolley systems. Just go straight to van systems, either van installed or diy system
Granted WFP Van mount is the way to go for sure.
But if on a tight budget all the same using a backpack to spray the roof with soap etc would be quicker that having to keep dipping the brush in a bucket surley. especialy if up a ladder having to move the pole each time and reach it back down to dunk it in the bucket?
Same goes for FSG cleans as the backpack could also be connected direclty to a wfp to apply soap etc from the brush head so you can control the amount you need at any one time with a simple tap or univavle fitted to the pole whilst giving the surface a scrub at the same time. Then you would rinse down by switching the wfp over to a garden hose contected to an outside tap.
If customers don't have an outside tap then yer scuppered really but you can get fittings to connect to an inside tap but are more hassle than they are worth. As already mentioned would be far too much hassle having to keep filling a backpack with tap water to rinse a conny roof down and/or FSG's. Then after all that you would still need to trad clean all the glass too.
That's when a wfp purified water van mount comes into it's own as you can do the whole lot with pure water if you wanted without having to mess about. When I say van mount you don't have to spend a fortune either as my so say van mount is just an old purefreedom trolley connected to a 250 L & 450 L tanks. I got for both tanks for 25 squid each from fleebay but the trolley, wfp's, hose reel etc I decided at the time to buy new. To make pure water I bought a ro/di and made myself a chepo static system using 1000 L ibc's
One day I may fit a pump box, controller & larger lesuire battery instead of using the trolley static in the van but that simple setup has worked well for me for yonks so I probably will never bother.
After saying that if you are lucky enough to work in a very soft water area (say around 40ppm) if you wanted you could produce pure water on demand onsite using a customers outside tap by using a 11 L di vessel filled with di resin that would bring the ppm of the water down to 000 ppm and do the lot using pure water. Likewise you could produce your own pure water from tap water too just by using DI's instead of having to use an RO/DI setup.