The reach of most sprayers will vary with the PSI. The higher the pressure and more directed spray, the further the reach. On average, at the highest PSI you can reach roughly 15-20 feet away using the Chapin Tree/Turf Pro 4 Gallon Backpack Sprayer (#62000) sprayer.
Yes, the 6-8182 Backpack Shoulder/Waist Straps that go with the Chapin Tree/Turf Pro 4 Gallon BackPack Sprayer (#62000 are available by special order. To place your order, please feel free to contact our customer service line at (866) 581-7378 during normal business hours (Monday-Friday, 9am-12pm and 1pm-5pm EST). Please mention SKU# 19347 to place your order as this is an item that we do not normally carry.
The Chapin Tree/Turf Pro Backpack sprayer is like any other hand pump sprayer, it typically will only reach about 10+ feet under pressure. Probably not enough to reach your roof line. We do carry another sprayer called a Slide Pump Sprayer that will reach up to 30 feet or more. There is a video on the slide pump sprayer page that shows it in action so you can see how it works. The slide pump sprayer is the only type of non gas or electric sprayer that will reach that far.