Top to bottom or bottom to top?

I believe it is a matter of water evaporating from a lower percent mix thus turning it into a more concentrated mix and causing streaking if not done bottom to top.
 
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I'm not a roof cleaning company but I'm sure it's the same procedure to cleaning other things. To avoid streaking apply your soap bottom to top and rinse top to bottom.
 
I heard we should wash roofs bottom to top but I see a lot of guys doing it top to bottom. Why? what is your method and reasoning?
Well ...... depends on which KIND of a roof.
Tile roofs have edges (Lips) that are easier to get if you work from the bottom up.
This forces the spray against the edges of the tiles, but the same thing can be done with an angled wand, or a ball valve turned sideways.
For shingle roofs, honestly, I have done them both ways, from top to bottom, and from bottom to top, and also sideways!
I never saw any streaking, no matter what way I did them.
However, to be "kind" to my groundman, I always tried to do the edges of the roof first, and then walked up the roof, and then went from the top down.
If you do the first 3 to 4 rows of shingles from the bottom of the roof first, it is fairly easy, once you get some experience, to not have any more run off, or very very little.

"Chicken Shit" roof cleaners stand at the top of the roof, and spray down, creating tons of run off, and a nightmare for your grounds people.
Once any potential roof cleaner shows any fear of heights in my company, he is finished here.
He can not work for us, because all our employees are cross trained, as they should be, in any small roof cleaning company.

It is no "Sin" to be scared of heights, hell, I am scared to get into an MRI Machine!
But fear of heights will cause you to get hurt, in the roof cleaning business.
 

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Chris hit a great point regarding tile roofs. You have to clean from the bottom to spray the tile edges, especially barrel tile roofs. Those edges can easily be seen from the ground and are the hardest part of the tile to clean. Shingle and metal roofs really don't matter what direction IMHO.
 
we clean roofs from the tops... why waste all that mix letting it run over something that has already been cleaned? spray from the top, let it run, see what it cleans and goes from there...

Im sure someone will come on here and say thats the wrong way- but thats how we clean siding also... never had a problem...EVER...
 
Chris hit a great point regarding tile roofs. You have to clean from the bottom to spray the tile edges, especially barrel tile roofs. Those edges can easily be seen from the ground and are the hardest part of the tile to clean. Shingle and metal roofs really don't matter what direction IMHO.
Everyone has a way that works for them. We actually climb on nearly every roof we clean.
Our friends up north might have a 3 story 10/12 pitch roof, and must spray from a ladder.
These almost have to be done from the Top Down, unless you want to blind yourself, and fall off the ladder.
 
John, I always teach to spray from bottom up on both houses and roofs. On houses for the reason of streaking and better more uniform coverage and limiting waste. On roofs because it really helps to control your run off as you are not creating a water fall of solution running down the roof when you spray top to bottom.

We to always spray the bottom two or three rows of shingles first with our gun pointing back up towards the roof, as opposed to standing back and letting it hit the edge and bounce off the roof edge onto plants below. Same with the sides. Now this works great for easy walkable roofs. For roofs that aren't walkable we will either 1) Spray from a ladder at the gutter line, again using the bottom to top technique, or 2) we often can times can find a way to get to the top ridge and spray from there. However, we will not spray the bottom 5-10 rows of shingles, instead we start up from there, leaving the 5-10 rows of shingles closest to the gutter line dry, and spray upwards towards the ridge. Then we either spray the bottom section which usually doesn't need a whole lot as the run off has run over it, or we will ladder up and hit from there. It takes a little time as we don't flood the roof and we often stop to let the mix soak in. But our goal is never to be in hurry and make sure the property is protected.

Hope that helps.
 
For me it depends on whether the roof is walk-able or not. If it is walk-able I generally start at the bottom and work up. If it is not I generally start at the top and let it run a little until it stops and then pick up. I don't think there is an evaporation effect like some have mentioned. I think working from bottom up is more about uniform coverage and reducing waste - when applicable....

Daniel Simmons
Pressure Washing America, LLC
Pearland house washing company
Sugar Land roof cleaning
 
Ok all. lots of great points. I did a roof yesterday. I did it from bottom up sideways in a sweeping motion. I watched the video on you tube of AC spraying a roof with very little run off. I too have have very minimal run off. I ran into the problem of the algae being so heavy in one area that I hit it twice And when i left it was obviously Dead but still visible. should this be left to the next rain or just keep hitting it until it is all gone . I use 10% from Leslies pool supply and use a 40% mix.
 
Ok all. lots of great points. I did a roof yesterday. I did it from bottom up sideways in a sweeping motion. I watched the video on you tube of AC spraying a roof with very little run off. I too have have very minimal run off. I ran into the problem of the algae being so heavy in one area that I hit it twice And when i left it was obviously Dead but still visible. should this be left to the next rain or just keep hitting it until it is all gone . I use 10% from Leslies pool supply and use a 40% mix.
I see that you are here in Florida!
Leslie's Chlorine sucks, seriously it does. Do you have a Pinch A Penny Store close to you ? If so, their SH is a Lot better then the Leslies stuff.

To answer your question, we can't always rely on the rain to do our job.
Our goal should be to leave a roof as clean as is possible, and only then rely on the rain to make it absolutely spotless.
When we tell a customer to "wait for the rain", they sometimes reply "Then WTF Did I Pay You For".

There are 2 things that discolor any roof, algae and dirt. It is up to you to remove the algae, then the rain will remove the dirt, once the algae is gone.
But we can not leave behind big missed spots of algae, then depend on the rain to remove them for us.

It is not unusual for us to have to hit some really thick "Florida Algae" spots 3 to 5 times.
 
I see that you are here in Florida!
Leslie's Chlorine sucks, seriously it does. Do you have a Pinch A Penny Store close to you ? If so, their SH is a Lot better then the Leslies stuff.

To answer your question, we can't always rely on the rain to do our job.
Our goal should be to leave a roof as clean as is possible, and only then rely on the rain to make it absolutely spotless.


When we tell a customer to "wait for the rain", they sometimes reply "Then WTF Did I Pay You For".

There are 2 things that discolor any roof, algae and dirt. It is up to you to remove the algae, then the rain will remove the dirt, once the algae is gone.
But we can not leave behind big missed spots of algae, then depend on the rain to remove them for us.

It is not unusual for us to have to hit some really thick "Florida Algae" spots 3 to 5 times.

I agree, I am here in Florida, I service mostly so far Volusia and Seminole counties. I Agree that when I do a roof I want to drive away with out a spot left. There is a pinch/penny around. They both are plentiful.
I currently use a 3.5 GPM 45 psi surflow, I think i need a larger pump for more volume to get better distance. As far as the spots go I was wondering if going 50 50 would be better or even TSP ( as if I know what TSP is )
 
Well ...... depends on which KIND of a roof.
Tile roofs have edges (Lips) that are easier to get if you work from the bottom up.
This forces the spray against the edges of the tiles, but the same thing can be done with an angled wand, or a ball valve turned sideways.
For shingle roofs, honestly, I have done them both ways, from top to bottom, and from bottom to top, and also sideways!
I never saw any streaking, no matter what way I did them.
However, to be "kind" to my groundman, I always tried to do the edges of the roof first, and then walked up the roof, and then went from the top down.
If you do the first 3 to 4 rows of shingles from the bottom of the roof first, it is fairly easy, once you get some experience, to not have any more run off, or very very little.

"Chicken Shit" roof cleaners stand at the top of the roof, and spray down, creating tons of run off, and a nightmare for your grounds people.
Once any potential roof cleaner shows any fear of heights in my company, he is finished here.
He can not work for us, because all our employees are cross trained, as they should be, in any small roof cleaning company.

It is no "Sin" to be scared of heights, hell, I am scared to get into an MRI Machine!
But fear of heights will cause you to get hurt, in the roof cleaning business.

My hands are sweating just reading this post and looking at the pic!
 
I agree, I am here in Florida, I service mostly so far Volusia and Seminole counties. I Agree that when I do a roof I want to drive away with out a spot left. There is a pinch/penny around. They both are plentiful.
I currently use a 3.5 GPM 45 psi surflow, I think i need a larger pump for more volume to get better distance. As far as the spots go I was wondering if going 50 50 would be better or even TSP ( as if I know what TSP is )
That Shurflo 45 psi 3.5 GPM pump is ancient technology! If you are using 3/8 or even 1/2 inch hose, going to 5/8 hose will be a huge improvement, because the larger the hose diameter, the less pressure and flow loss there is.
Remember, you want your hose to be as fat and as short as is possible. The pump you are using only has 45 psi open flow, so you must be careful not to piss away what little pressure you have.
Some of our roof cleaners at the roof cleaning institute are using these pumps http://www.northerntool.com/shop/tools/product_200578549_200578549
Compared to what you have now, these pumps will spray like a Male Cat.

They have a non commercial replacement warranty, and if they fail, rinse em off really good so you do not smell bleach, and tell them they were a water pump for your RV !

We clean shingle roofs daily with a 25 to 30% solution (25 to 30 gallons of SH to 70 to 75 gallons of water)
Back 18 years ago, when I used pumps like you are using right now (with skinny hose), I had the exact same problems!
 
I see that you are here in Florida!
Leslie's Chlorine sucks, seriously it does. Do you have a Pinch A Penny Store close to you ? If so, their SH is a Lot better then the Leslies stuff.

To answer your question, we can't always rely on the rain to do our job.
Our goal should be to leave a roof as clean as is possible, and only then rely on the rain to make it absolutely spotless.
When we tell a customer to "wait for the rain", they sometimes reply "Then WTF Did I Pay You For".

There are 2 things that discolor any roof, algae and dirt. It is up to you to remove the algae, then the rain will remove the dirt, once the algae is gone.
But we can not leave behind big missed spots of algae, then depend on the rain to remove them for us.

It is not unusual for us to have to hit some really thick "Florida Algae" spots 3 to 5 times.

Hi Chris. I am using Leslie's SH too. I got them down to $1.20 a gallon if they fill my tank and $1.58 if I get a jug. I did notice that sometimes it cleans good, and sometimes it just doesn't seem to do anything. Is pinch a penny chlorine stronger and more consistent? I'm not cleaning roofs, but having a weak mix causes me to go over a driveway again and again sometimes. It's irritating. Do you know how much pinch a penny costs per gallon and do they have business accounts that you can pull up in the back and fill up?
 
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