I attached photo of stucco chimney that is dirty. Dirtiest one that I've ever attempted. It was a neighbors house from a job, we cleaned, and while wet there was still showing staining, but much less. I told homeowner to let it soak in and we will look at again later. I stopped by today but it was wet from the rain today and I couldnt tell if it was better or not. I am going by house Saturday, if stain still there, is there any other options I could try? Would gutter grenade work or a CLR?
Two things, 1) hotter mix ( might have to go up as high as 50%) 2) might need a little pressure with algae this severe, but be careful, as that can damage stucco
Also, prepare HO that pigment in stucco could be shot. Sometime while if gets this bad ( face it, this is a problem that has occurred over several years), the algae will "eat" the imbedded pigment in the stucco or paint that is covering the structure.
Gregg Austensen said
Oct 4, 2012
Once you've gotten it looking as best you can recommend to HO to have kickout flashings added at chimney to direct water into gutters. The lack of these is what led to the stains. You might want to test some type of degreaser as there may be some asphalt staining.
Tim Teed said
Oct 11, 2012
here is an after photo of the chimney. I told my son to take a photo before he did the second treatment-but of course he didn't. He just sprayed with a 3% mix the 2nd time. He said it was pretty good without the 2nd treatment. This photo is the final after photo. Everything was 3% strength with Greenwash. $250 job we got canvassing neighbor while we were doing a neighbor.
I attached photo of stucco chimney that is dirty. Dirtiest one that I've ever attempted. It was a neighbors house from a job, we cleaned, and while wet there was still showing staining, but much less. I told homeowner to let it soak in and we will look at again later. I stopped by today but it was wet from the rain today and I couldnt tell if it was better or not. I am going by house Saturday, if stain still there, is there any other options I could try? Would gutter grenade work or a CLR?
2) might need a little pressure with algae this severe, but be careful, as that can damage stucco
Also, prepare HO that pigment in stucco could be shot. Sometime while if gets this bad ( face it, this is a problem that has occurred over several years), the algae will "eat" the imbedded pigment in the stucco or paint that is covering the structure.
here is an after photo of the chimney. I told my son to take a photo before he did the second treatment-but of course he didn't. He just sprayed with a 3% mix the 2nd time. He said it was pretty good without the 2nd treatment. This photo is the final after photo. Everything was 3% strength with Greenwash. $250 job we got canvassing neighbor while we were doing a neighbor.