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Sidesaddle · Guest

What went wrong? More dark streaks after apple cider

Roof Cleaning Missouri 417-230-8103 · Guest

You have any pics , and how thick was the algae on front of roof ?

KID

Roof Cleaning Wallace N.C 910-463-8400 · Guest

Don't panic brother.this happen on my first roof. sounds like your batch is to Weak.strengthen it up and blast it again.

hmm,what was you batch ratio?

Sidesaddle · Guest

I used 15 gal of sh 12.5% (supposedly), 25 gal of hot water, 5 lbs tsp, 64oz of iso alcohol, 32 oz of dawn. Last fall I did a roof with the same same recipe and also added borax and it was very good at cleaning. I'm thinking due to the cooler temps and weaker sh maybe I need to increase to 20 gal or sh? Thanks!

Sidesaddle · Guest

Here is the before picture, don't think I took an after unfortunately. The lichens died right away.

Sidesaddle · Guest

OK found an after photo, seems the roof is darker over the garage now. Do you think that after a few days the dark areas will lighten after drying? This side of the house was in constant shade yesterday.

Baltimore MD Roof Cleaning 410-482-4367 · guest

I can't see your pics bro. May be my phone.

Reliable Roof Cleaning Jacksonville FL · Guest

It's difficult to tell anything from the before & after pictures. The problem is that they are of two different distances and angles. Not good for comparision. Take an after picture of the garage roof at the same distance and angle.

Charles

Midtown · Guest

Baltimore MD Roof Cleaning 410-482-4367 wrote:

I can't see your pics bro. May be my phone.

I had to rename it to add the extension.

Sidesaddle: That's not coming off most likely. You need to respray. I think your SH was old or the roof was real bad.

Guest

Very Important: Did you rinse this roof?

-- Edited by Roof Cleaning Evansville Indiana 270 860 7894 on Tuesday 2nd of March 2010 12:31:42 PM

Mar 2, 2010

The mix should have worked without a problem.From the before and after picture it seems the black algae was not affected at all. The photos show that the roof was done in the shade.There is a chance it may be gone when you go back,in cold weather it takes alot longer to react. If it is not gone I would suggest this, increase the sh strength like you said.....every thing else the same hot water and all. But I would try to find when the sun will be on those shingles and do it then.

Baltimore MD Roof Cleaning 410-482-4367 · guest

The water temp is important as well. Too hot willbreak down the chems, I suggest under 90 f.

Evergreen · Guest

We had the same problem this past sat. Same weather conditions and the same mix as well. We ended up using a second coat on the black streaks that were still pronounced. By the time we were cleaned up and about to leave the streaks were almost gone and what was left was faded. We are headed back tomorrow to see if they have fully cleaned up. Maybe the heavy black streaks just need a 2nd coat.

Sidesaddle · Guest

I did not rinse the roof afterwards.

Sidesaddle · Guest

Wow, thanks for all the kind replies!

Good points on the water not being too hot. I premixed the tsp with about 25 gal of 120F water, added it to the tank and added the sh and iso just before arriving at the job site 2 hours later.

Now that I think about it, I used sh from the same batch to clean the siding and it did take a bit more than normal to remove the green mold so probably the sh is old being that the supply shop hasn't been selling much over the winter.

It'd be nice to have a test kit and get the mix more precise, anyone know of a good sh test solution?

I'm planning on a second application on that roof but this time I'm waiting for a 60 degree plus day and I'm going to make sure the sh is smoking when I buy it.

Thanks again for all the suggestions.

Baltimore MD Roof Cleaning 410-482-4367 · guest

I hope we helped . Welcome to the forum.

Guest

I learned a long time ago not to beat my head against reasoning out why the same mix on the same type day doesn't work the same. Because just as soon as you think you've got it figured out, it happens again, ha,ha!! Using a determined mix and adjusting to the conditions is just about all you can do,...after these basics are taken care of,...all there is to do then is spray and respray,....and move on. Otherwise you'll be changing things constantly and not really getting anywhere but confused.

Jeff

Sidesaddle · Guest

Thanks Jeff, good advice. I know what I really should do is make a smaller batch such as 20 gal, try it out, then adjust accordingly the final batch at the job site. Warm weather is finally in sight here in VA so that'll help the process.

Thank you,

Mark

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Roof Cleaning Wake Forest NC 27587919-412-2432

Roof Cleaning Wake Forest, Raleigh, Knightdale, Rolesville, Youngsville NC

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Roof Cleaning Wake Forest NC 27587
919-412-2432