Black Streaks on Roofs

[piedmontpw276]

Hello, my husband has been using our house as a testing area for setting up his chemicals and getting them to the right strength stuff like that.

He is using the TSP & Bleach/water mixture on the roof and it did clean it and lighten it up but he is having a hard time getting rid of the black streaks. My question is - What can he do to get rid of these streaks without having to get up on the roof? he tried scrubbing with a scrub brush on a broom handle, but that is not quite doing it. Should he make his solution stronger or is there somthing else out there he should be using or trying?

Thank you!!

Donna
Piedmont Pressure Washing

[CaroliProWash]

It could be the strength he is using or the dwell time - I'll direct some of the roof guys to this thread to see if they can expound on this

[piedmontpw276]

Thank You!!

[Christopher]

Hello Donna, How are you doing?

I have been doing a lot of that on my roof also, so I know how you feel. I do roofs.

Feel free to give me a call, have a pen and paper ready.

[Scrappy]

4000 PSI and a turbo nozel lol i'm kidding i'm kidding DON"T DO THAT LOL


its most likely your mix . . . get the strongest sh you can find . . just using bleach is a pita imo . . .. maybe try to mix it stronger and let it set longer . .. hope this helps

[newbie pete]

What are you using to apply the chemical. If he's using an x-jet or downstreaming it then it might be too diluted. If hes using a shurflo or Delevan diaphragm pump the try using 1/1 bleach to water with some tsp mixed in. I'm no expert but thats what they say works.

[DAFF]

Myself I like to wash those chemicially chalanged jobs first thing in the morning or during a wet and dreary day. Seems silly to the customer but after you convince them of how the sun and heat works against you and the finial product they seem to like the idea. Plus it open up the work week for the days it is not raining. Best of all you save $$ and time not fighting the dry/wet game and let the chemicial do its work!!

DAFF

[newbie pete]

Piedmont your in Virginia right. Whats the air temperature down there. If it's around 50 degrees that might be your problem.

[Barry M]

Originally Posted by DAFF

Myself I like to wash those chemicially chalanged jobs first thing in the morning or during a wet and dreary day. Seems silly to the customer but after you convince them of how the sun and heat works against you and the finial product they seem to like the idea. Plus it open up the work week for the days it is not raining. Best of all you save $$ and time not fighting the dry/wet game and let the chemicial do its work!!

DAFF

That's funny I've always thought cleaning roofs works better on dry hot days. Shingles don't absorb as well on cool cloudy days, and I'm not big on walking on a wet roof more than I have too. That's just me though.

The problem is more than likely too weak of mix or old chlorine. That stuff has to be fresher than fresh to work good. It needs to be hitting the roof at about 4-6% to be effective.