As someone who is fairly new to roof cleaning ill give you my .02
First before you even do a customer roof you need to practice on your own, a neighbor, family or friends roof. Killing grass and plants not only looks bad its expensive.
Their are a lot of things only experience will show and tell you. The chart will only help so much, for roof most of us any where from a 3%- 6.5% mix it really depends on how bad the roof is, type of roof material and how fast you want it to work. With a lighter mix you usually will have to spray again (at least some areas), with the hotter mix you can do it all in one pass. I know a guy who uses an even hotter mix at about 8%-10% , his philosophy is time is money he rather do it all in one controlled quick pass and on to the next job. Also different roof materials will need a weaker or hotter mix. This is where the proportion or similar system come into play. When you are using a drum and let say you make a 3.5% mix you start spraying only to realize its not hot enough for your liking. You now have this 50 gal drum you have to try to re-calculate to make hotter. Thats why it can be very advantageous to use a pump up sprayer and try the mix first before making a drum of it.
2: i have a hose reel and have a little over 200 feet of ag hose and its a pain with the reel so i feel for ya.
3: Different situations will call for different things. If some plants get so much as a drop of SH they will die, so you have to do both some times. Also you should have a someone watering anyways whether you tarp or dont. The second person (water guy) is probably more important than the one spraying the roof. Even from a safety stand point you need a second person with you for roof cleaning.
4: If they have gutters i highly suggest you bag them, Even thick soaps can and will run down steep roofs, this is where experience will help.
5: i spray roof dry, it preference. When the roof is wet the asphalt is saturated so when you spray your mix, it floats on top and run faster. This means more coats, and potentially more run off.
6: Its going to suck in air, it wont damage it when your priming it. If you can pre-prime it a little by getting some water further up the tubes, it wont hurt
Theres is a lot to learn and know,
A lot of guys try to shoot from the gutter line. While i understand why, i try to walk roofs, this allows me to spray a hot thick coat and get a more even coverage on the roof. When you shoot from the gutter line it means the mix will run. This is not as big of a problem if you have gutters all the way around. Where i live most average size home do not have gutters. When a 4% mix rolls off the roof i dont care how much you water its going to kill the grass.
You also have to be careful of the mist from spraying, i killed a tomato plant that wasnt even near the roof just the mist. If theres even a slight chance of rain i reschedule, if it rains too soon it can wash a hot mix off the roof and burn a line in the grass (if no gutters) or put a nice big burn spot at the gutter spouts. Its also you decision on if you want to rinse a roof or not.
I highly suggest you check out the roof forum and really practice a roof first before you do a customers.
