Metal Roof Coatings

[john the architect]

start with plain zincalume and be done with it. Best for catchment next to stainless steel.

John Maloney
310.562.0362
johnmaloney3@me.com
Hawaii Architect AR8082

[1voyager1]

quote:

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Originally posted by 1voyager1

Our roof is about 10 years old now.
It is beginning to form large black areas that appear to be something similar to the steel corroding under reducing conditions, or a residual from the original finish degrading.
I'm certain that it is not mold, mildew or other similar type growths.
It is also forming minor rust areas along the lower edges. .....

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Went up today and cleaned the screens on our downspouts.

While doing that, I saw this:

http://s131.photobucket.com/user/solo_vo...c.jpg.html

That tells me that, in no uncertain terms, some type of creepy crawler is eating the black residue on our roof.
It is not corrosion.
it is some kind of algae or fungal type growth on the roof.
I then took the scrub brush and bleach water I was using on the screens and scrubbed the area just to the right of the nibble tracks.
It cleaned right off.
Now I need to get ready to clean off what ever is growing on our roof.

http://s131.photobucket.com/user/solo_vo...k.jpg.html

A scrub brush does do the job.
but, I don't see me on my hands and knees scrubbing a 2500sqft roof with a kitchen scrub brush.
I do have a pressure washer that I'm considering using to clean the surfaces of the PV panels on the roof.
I'm not sure if it would do the job on the growth though.

Thought, ideas, suggestions???

[Obie]

Wet and forget !

http://www.acehardware.com/product/index.jsp?productId=35090396&KPID=18508736&pla=pla_18508736

[1voyager1]

Thanks Obie for pointing me towards that product.
I was leery of what it was composed of due to the roof being part of our catchment system.

From their website the active ingredient is Alkyl dimethyl benzyl ammonium chloride, a quaternary ammonium chloride.
I used to use this type of algaecide/fungicide as a surface treatment for fungal infections on my orchids in AK.
It is used as a pond algaecide and other applications.
In the correct concentrations it is classified as a food grade disinfectant.

Following your link, the Wet & Forget is a 10% concentration selling for $37/gal @ Ace.

HD has POOL TIME ALGICIDE, a 20% concentration of the same active ingredient for only $11/ gal.

The W&F may contain other ingredients that may affect how it holds to the surface it is applied to, but I'm thinking that it probably does not.
The weather forecast for the next week seems to be indicating that we're in our winter drought right now.
I think that I'll run into town and pick up a couple of gallons of the pool algaecide.
Then, disconnect my down spouts and spray the roof with it mixed per the W&F making a 2X concentration.
I can leave it on for the duration of the "drought".
Its being wetted every evening by the dew formation will activate it each night until the rains wash it off.
Then maybe a final pressure wash of the roof to clean it all off before hooking the downspouts up again.

Lately, I've been wondering about the need to clean our PV panels.
They've been up for over a year now.
They are probably getting a coating on their surfaces blocking some of the sun..
A cleaning should improve their efficiency at least a mite.
I may spray them too, or just pressure wash them later after checking for potential bad effects.

[David M]

Please post how well this works. I was thinking of using the W&F on concrete, but the pool algecide is much more reasonable if it works.

David

Ninole Resident
Please visit vacation.ninolehawaii.com

[1voyager1]

Went to HD yesterday and looked for the Pool Time Algecide.
I was wrong.
It was in 1/2 gal bottles @ $11/ bottle.

I did find it in quarts at 50% strength for $16/qt.
I bought 2 qts.
Assuming that is 50% by volume, they will make 2-1/2 gallons at 10%.
More than enough to treat our roof and the "black" areas on our exposed concrete pads and walkways.
Got side tracked by working on M'Lady's web site and on building some cabinets.
Don't know just when I'll get around to applying it to the roof, maybe tomorrow?

Take note that all three projects are at her insistence.

[birdmove]

As I started through this thread, I was going to ask you if you had tried cleaning it. Our roof is from 1996, and hassome of what you described. I made a cleaning tool and tried it out, and it took that stuff off. I bought a small cleaning brush, I think from Home Depot. Got one with a flatter handle. Drilled a couple holes in the handle, and used 2 deck screws and attached it at the end of a 1x2 8 feet long. Tried it on a section of our roof that has no gutter, as it must have been an ad-on for the back porch. Since no gutter, I didn't have to worry about covering the gutter to keep the dirt from getting into our catchment. Just used the brush and plain hose water, and it worked very well. I was able to do most of that while standing on our 8' A frame ladder. I may make a longer cleaning brush for other parts of the roof. At 62, I'm not real excited about climbimg all over our roof.

You could also hire someone to clean your roof. Now that you seem to know the stuff will clean off, you know what to do. I figured, if I do the rest of our roof, I'll either cut some plywood to use to cover the gutter while I'm cleaning a section, or disconnect the downspout from the gutter.

Jon in Keaau/HPP

[1voyager1]

@ birdmove
I understand your lack of enthusiasm due to age.
I've got an additional 10 years on you, plus I'm all but blind in one eye.
I've found that I'm very unsteady and lack my usual confidence while wandering around our roof.
I've never liked heights.
That dislike has magnified with my present condition.
I've decided to pick up a roofer's fall protection kit, but am finding it hard to find one useable on, or adaptable to, a metal roof at a reasonable price.
The problems I see are getting the anchors mounted securely and protecting the ridge cap.

Code:

QUOTE:
"... You could also hire someone to clean your roof. ..."

Not an option yet.
I've never been one to hire someone to do something I can do myself.
Plus, when I've finished the job, I've usually got the tools left over for the next time, all for less than hiring someone.
I expect to get it figured out fairly soon.
We'll see.

[Vic]

quote:

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Originally posted by 1voyager1

Not an option yet.
I've never been one to hire someone to do something I can do myself.

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I agree with your take.

Cant wait to live in Puna!