In the area where I live we have a lot of concrete tile roofs. The problem I am referring to is white areas looks like spots on the roof. I did my research online and some people saying it is calcium carbonate or Lime. It can be cleaned with some acids like (muriatic acid or acetic acid). I tried them both in a different concentrations. Almost no result.
Does anyone had successful experience with cleaning this?
The white spots look like Lichen to me, which can be killed using SH. (if that's what it is)
Nikolas153 said
Aug 8, 2017
I wish it was the Lichen, but I don't think so. I tried strong acids and SH too - nothing works, only pressure washing.
Jeff Wible said
Aug 9, 2017
I'm with Zach,..I think it's lichen,..especially the way the "grouping" looks. Just looks like typical lichen. What makes you think SH isn't working? Because of it's light color,..lichen doesn't show as dramatic reaction to SH as other molds and/or moss type growth. And it isn't gonna disappear upon application.
Jeff
Eric Schnaible said
Aug 9, 2017
Jeff Wible wrote:
I'm with Zach,..I think it's lichen,..especially the way the "grouping" looks. Just looks like typical lichen. What makes you think SH isn't working? Because of it's light color,..lichen doesn't show as dramatic reaction to SH as other molds and/or moss type growth. And it isn't gonna disappear upon application.
Jeff
Yes, what Jeff said. We run in to that lichen all the time. The SH definitely kills it. It just doesn't change much visually. Give it time. Any dark bacteria stains should be gone though.
Nikolas153 said
Aug 9, 2017
Jeff,
two reasons why I think it is not Lichen:
1) It does looks like calcium buildup from concrete tiles and it is very strong.
2) I tried 3% SH solution on it, waited for one hour, then rinse it off with water - no results
If it is Lichen, maybe I should try stronger SH solution?
My costumer wants instant result, it means by the time I finish cleaning white spots should be gone without using pressure washer on the roof.
Eric,
How long should I wait after SH application? I have to find the way to completely clean it by the time I am finishing project.
Thank you.
Eric Schnaible said
Aug 9, 2017
If it's lichen, you should be able to manually remove, brush/scrape it off. Is it actually hard like efflorescence build up? Any chance it bird turds?
Jeff Wible said
Aug 9, 2017
3% isn't gonna touch lichen. That's nothing more than glorified house wash mix. It needs to be zapped really good to kill it dead. When a customer WANTS instant results,..be sure they pay for those instant results. Remember,..it's not your fault the roof is in the condition it's in,.and the customer can pay for what it takes to get those results.
Jeff
BlueRidge said
Aug 9, 2017
Jeff Wible wrote:
3% isn't gonna touch lichen. That's nothing more than glorified house wash mix. It needs to be zapped really good to kill it dead. When a customer WANTS instant results,..be sure they pay for those instant results. Remember,..it's not your fault the roof is in the condition it's in,.and the customer can pay for what it takes to get those results.
Jeff
Nikolas153 said
Aug 10, 2017
Unfortunately it's not the bird stuff.
Jeff, thank you for your suggestion. What percentage do you think I can use to clean it at the same day? assuming customer is ok to pay.
And why strong Muriatic Acid didn't work?
Eric Schnaible said
Aug 10, 2017
I figured 3% meant 30%, Which should do the trick.
This is probably stating the obvious for most but I'm throwing it out there for clarity.
Most of us receive our SH at 12.5%. subtract 2.5% for any loss of strength for multiple reasons. (and because it makes for simple math). That gives you a standard working strength of 10% SH. A standard roof mix is 30%. The actual % of pure SH would 3%.
These percentages also sound better when the homeowner says, "Is that bleach?". "Yes Ma'am, our solution contains 1%-3% bleach". That doesn't sound so bad. And if they think they found our "Secret", their 3% household Clorox will never work.
On another note. I wouldn't use muriatic acid on concrete tile if I were you. Thats just me.
Jeff Wible said
Aug 10, 2017
For just black streaks 3% will work,..although I'm still at about 4-5%. But lichen needs zapped really good to make it loosen it's hold so it can fall away. Even with just black streaks,.. I'd rather spray a little less total mix than have to spray more times with a lighter mix. Pitch of the roof can also play a role in the strength I use. Now,,on a cement tile roof or slate,.and if I'm dealing with lichen,...that I want soft enough to (Hopefully) rinse away without having to be directly on it,...I'd be at about 5-6%,..along with some NAOH added for extra punch. The cement will handle the NAOH,.where asphalt shingles will not. But NAOH will compliment SH very well in this situation and help the softening. Use extra surfactant so it hangs onto the lichen allowing the mix to penetrate into it.
*But, nothing is gonna be able to be sprayed onto the lichen and have it just go away. So,.if you have access to the lichen,..just use regular roof mix and remove it with your washer.
** Erics right,..muriatic acid on cement shingles could darken them or even remove the top finish,..if it's still there.
Jeff
Fred W said
Aug 10, 2017
3% works just fine in our neck of the woods for Lichen.
Eric Schnaible said
Aug 10, 2017
Yeah, for us too. In my area we have quite a diversity with lichen and algae types. Some are very hardy and tenacious. As mentioned earlier by Jeff, they really don't change much visually when hit with the juice. We also have certain types of lichen that grow great where zinc leaches from sheet metal. Zinc usually keeps those areas clean. Its kind of silver, white, light green. I'll post some photos when I get back from England in a week.
Jeff Wible said
Aug 10, 2017
3% will work,..considering he is going to PW it off. But for easier removal and "instant" results cleaning,... (Like he's wanting to do here),....a stronger mix is always better,..especially for hard to rinse areas,..where you may not be able to get right on it. It breaks the lichen down and softens it which allows for easier rinsing. .
Jeff
-- Edited by Jeff Wible on Thursday 10th of August 2017 03:24:32 PM
Fred W said
Aug 10, 2017
In our area we just don't need to go stronger Jeff. 3% takes care of it really well.
Nikolas153 said
Aug 11, 2017
Thank you for suggestions. I will try stronger mix on my next project, and see how it goes.
Jeff Wible said
Aug 11, 2017
Baton Rouge Roof Cleaner wrote:
In our area we just don't need to go stronger Jeff. 3% takes care of it really well.
I think the difference may be in the strength of the SH we get,.yours may be stronger? Either way though,.if he's PW'ing off a basic mix will work.
Jeff
Fred W said
Aug 11, 2017
We buy it at 12.5% but I do know it comes in stronger at times. I used to get a printout when I used Univar and from them we usually ran close to 13%
Cleanupcrew said
Aug 16, 2017
From a job last week.
They are terra cotta clay tiles that get bad with lichen.
A couple of hits with 3% SH makes it so much easier to pw it off.
Hi there,
In the area where I live we have a lot of concrete tile roofs. The problem I am referring to is white areas looks like spots on the roof. I did my research online and some people saying it is calcium carbonate or Lime. It can be cleaned with some acids like (muriatic acid or acetic acid). I tried them both in a different concentrations.
Almost no result.
Does anyone had successful experience with cleaning this?
Thank you.
Jeff
Yes, what Jeff said. We run in to that lichen all the time. The SH definitely kills it. It just doesn't change much visually. Give it time. Any dark bacteria stains should be gone though.
two reasons why I think it is not Lichen:
1) It does looks like calcium buildup from concrete tiles and it is very strong.
2) I tried 3% SH solution on it, waited for one hour, then rinse it off with water - no results
If it is Lichen, maybe I should try stronger SH solution?
My costumer wants instant result, it means by the time I finish cleaning white spots should be gone without using pressure washer on the roof.
Eric,
How long should I wait after SH application? I have to find the way to completely clean it by the time I am finishing project.
Thank you.
Jeff
Jeff, thank you for your suggestion. What percentage do you think I can use to clean it at the same day? assuming customer is ok to pay.
And why strong Muriatic Acid didn't work?
This is probably stating the obvious for most but I'm throwing it out there for clarity.
Most of us receive our SH at 12.5%. subtract 2.5% for any loss of strength for multiple reasons. (and because it makes for simple math). That gives you a standard working strength of 10% SH. A standard roof mix is 30%. The actual % of pure SH would 3%.
These percentages also sound better when the homeowner says, "Is that bleach?". "Yes Ma'am, our solution contains 1%-3% bleach". That doesn't sound so bad. And if they think they found our "Secret", their 3% household Clorox will never work.
On another note. I wouldn't use muriatic acid on concrete tile if I were you. Thats just me.
*But, nothing is gonna be able to be sprayed onto the lichen and have it just go away. So,.if you have access to the lichen,..just use regular roof mix and remove it with your washer.
** Erics right,..muriatic acid on cement shingles could darken them or even remove the top finish,..if it's still there.
Jeff
3% will work,..considering he is going to PW it off. But for easier removal and "instant" results cleaning,... (Like he's wanting to do here),....a stronger mix is always better,..especially for hard to rinse areas,..where you may not be able to get right on it. It breaks the lichen down and softens it which allows for easier rinsing. .
Jeff
-- Edited by Jeff Wible on Thursday 10th of August 2017 03:24:32 PM
Thank you for suggestions.
I will try stronger mix on my next project, and see how it goes.
I think the difference may be in the strength of the SH we get,.yours may be stronger? Either way though,.if he's PW'ing off a basic mix will work.
Jeff
From a job last week.
They are terra cotta clay tiles that get bad with lichen.
A couple of hits with 3% SH makes it so much easier to pw it off.