Very hard to put an exact number to it, because of the variables....temperature, wind, color of shingle, pitch, siding or stucco, stream or fan tip, etc...
here is what we typically use based on 50 gallon tank;
average home shingle roof (20-23/Sqs), not white three tabs = 20-30 gallons
average vinyl siding home (2000-2500/SF) = 25-35 gallons
add in wind, multiple touch ups on the roof, dormers or cut up roofs, and those numbers will increase.
Thanks John, I was thinking around a gallon a square. I am surprised that siding uses more, I would have thought slightly less than roofs. Thanks again.
I am interested in more input on this topic. I have been SWing for 2 years now, but have really only been doing siding. No one washes roofs in Wisconsin, and I intend to change that. So I did my first roof today, about 45 square of 3 tab light grey. I used almost 90 gallons of 4%. Streamed about 1/4 of it, and had to touch up a little less than 1/4 of it. Wondering if I used too much, or should I maybe figure on 2 gallons per square. Oh, it was barely 50 degrees, and average dirty on north facing aspects.
As I am used to cleaning siding, this seems like A LOT of chem. I did what I feel like was a ton of rinsing. Did all the siding on the same single story house with 50 gallons of 1%, then more rinsing. Finished with 2 hose end sprayers of plant wash.
My input on the siding amount, most "normal" bigger homes can be done with 50 gallons of 1%. Complexity of the design matters a lot. One of the easiest homes I have done was probably almost 5000 square feet, but it was a single story ranch, not very dirty, fiber cement siding, and a hip roof with no gables.
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Chad A. Eneix, President, Water Dragon Inc. chad@waterdragoncleaning.com
I wish there was an easy to use calculation, but sadly there is not. Its kind of a learn as you go and constantly readjust. Some days I'm shocked by my amount of chem usage, some days I'm pleasantly surprised. I know this last two week period we used $1400 in SH, I was shocked to see that check cross my desk, especially considering we did very few roofs due to a rainy week. Typically i'm only $1200 per month!!!!! But we also soft washed a whole townhouse neibghorhood full of driveways, and due to wet conditions had to spray them at 60%.
-- Edited by Ray Burke on Saturday 3rd of May 2014 01:30:49 AM
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Spray Wash Exterior Cleaning, LLC.
Cleaning North Florida, South Georgia, and Tallahassee!!!
Soft washing, pressure cleaning, and Safe roof cleaning!
that sounds about right for that white/light grey three tab. They typically use the most chems. Sometimes we get away with a tank on a roof that size, sometimes we don't. Depends on the pitch, amount of growth, wind, temps, and who is spraying it. On white three tabs we use a 4% mix, and 64 oz of Green Wash, and this seems to work well. We usually get away with one coat and very minimal touch up. All other shingles for the most part, we use a 2-3% mix and have no issues. I also think how fresh your SH is has a lot to do with it. We switched to Univar mini bulk this year, and it is extremely Fresh. Most every house wash only needs 2-3 gallons and most every roof has been 10-13, all calcs based on a 50 gallon mix tank. My guys commented to me the first day of the season this year, how fresh and strong it seemed, so they backed all the mixes down. It is very nice to have fresh SH, like Bill Booze has stated many times.
