The Roof Cleaning Institute Of America Training & Certification Forum
"Find A Certified Roof Cleaner Directory"

Apex Roof Cleaning · Guest

Question about stucco cleaning.

Roof Cleaning West Chester PA · Premium Member Roof Cleaning Institute of America

Hey Dan, when you say 40%, did you downstream or are you talking roof pump?

Oct 23, 2012

Apex Roof Cleaning wrote:
I had a stucco cleaning today, that really didn't come as cleaned as I would have liked. I have never cleaned stucco before, but I assumed I would use the same method as we always do. Start with a 10% solution and work my way up to a 40% if it woudn't come off. Well I started with the 10% and then moved up to a 40%. The stucco wouldn't come clean. There was green algae growing at the bottom, which all came off. Then there was these smaller black streaks in the middle of the wall, which wouldn't clean up? I used a fan tip with a pressure washer, making sure to becareful, but still nothing.
This was a business, on a busy road. There was a lot of grey dust in the window sills that all went away with the pressure washer. I will try and get some pictures.
Dan

Sometimes, if the algae has been there long enough, it actually stains the stucco. I see it often along the bottom 1' of stucco houses.

I warn the customer, that that area will probably still look gray.

MJ · Oct 23, 2012

I use TSP on stucco, light brush and rinse, and then rinse, we pre wet the surface and the black, which I think is dead algae, mildew looking like falls off. I was told bu a stucco contractor that TSP was the way to go, with bleach, no wand work, just make sure no cracks are in the stucco, I do not clean stucco, effis with cracks. We don't use heat on stucco.

Apex Roof Cleaning · Guest

Roof Cleaning West Chester PA wrote:
Hey Dan, when you say 40%, did you downstream or are you talking roof pump?

roof pump.

We all know, how well vinyl siding cleans up. Looks brand new. Stucco just wasn't giving me the same result. There is a larger 3 story business also on a main rd, has stucco siding. They want an estimate done in the spring, I need to make sure I can clean it before I give them an estimate.

Also tsp and a brush is not gonna be an option, there is way to exterior for that method.

Roof Cleaning West Chester PA · Premium Member Roof Cleaning Institute of America

Maybe dwell time was the issue? If it's not coming off I don't think it's cause you didn't use TSP. I just go with roof mix, typically 20-30%, but I let it dwell 10 minutes.

Apex Roof Cleaning · Guest

This is why, I don't think it was algae. I hit it with a 10% 5 min dwell, then a 40% 10 minute dwell. It wasn't touching it.

Roof Cleaning Raleigh NC · Oct 23, 2012

It isn't algae

sweetwaterfish · Guest

i would love to see some photos...somethings not adding up. sounds like you did everything right.

Apex Roof Cleaning · Guest

Here is the streaks I am talking about. It isn't algae, or it would have vanished.

waxman18324 · Premium Member Roof Cleaning Institute Of America

Apex Roof Cleaning wrote:
Here is the streaks I am talking about. It isn't algae, or it would have vanished.

Dan,

It looks as if the customer has a moisture intrusion problem. Prior to 1997 most installations didn't have a secondary weather barrier. Any moisture that infiltrates the system will become trapped between the exterior material and the sheathing.

Hank

-- Edited by waxman18324 on Tuesday 23rd of October 2012 06:45:13 AM

-- Edited by waxman18324 on Tuesday 23rd of October 2012 07:05:36 AM

sweetwaterfish · Guest

Are they all over building or just in that one area? If just in that one area I'm guessing is a roof leak causing mold & mildew behind the stucco/finish. If that's the case, it won't come out.

Doug R · Guest

Take a little SH full strength in a small squirt bottle. Spray some on a small area and see what happens.

Oct 23, 2012

Wow....I'm staying away from stucco!

Apex Roof Cleaning · Guest

It was it two spots. It was in that spot in the front ( no where else in the front), and then on the ride side of the building. No place else. Hank and Ray I think you guys are right, I think something maybe behind the stucco. But what do you tell this business owner? I don't think they can repaint it, because its going to show through again.

Dan

MJ · Oct 24, 2012

Looks like Dry-Vit, stucco around here is 1/2 think, EFIS is thin, knock on stucco and it and you here a solid thud, Dri-Vit, you here hollow ping. We work with stucco contractors on cleaning old world German stucco. it can moisture tested and see what that tells you, we see painted Dri-Vit, I turn down EFIS cleaning just because of expectations and most of the time it has been neglected past the point of getting good results. Cracks can be a liability for cleaning, the black looks inset, not surface. You can't hardly get a loan on a dryvit house in the Midwest, many were not installed and flashed right, till about 2001

Roof Cleaning Tallahassee · Guest

sweetwaterfish wrote:
Are they all over building or just in that one area? If just in that one area I'm guessing is a roof leak causing mold & mildew behind the stucco/finish. If that's the case, it won't come out.

+1

Apex Roof Cleaning · Guest

Well, there is another building on a busy highway it looks to have the same type of streaks growing on 3 of the 4 sides. I'm nervous, is it moisture or is it, algae. I may have to do a covert op mission, and spray a test spot at midnight to see what happens.

waxman18324 · Premium Member Roof Cleaning Institute Of America

Dan,

I just emailed you some info on this subject. Nothing secretive just the differences. I trust this will help.

Please no covert operations at night.

Hank

Roof Cleaning Katy Texas (281) 392-2304 · Oct 25, 2012

I have seen buildings like that beside roads where the car smog stained the building. No, SH will not take that out, nor will high pressure. What is odd is that the entire side of the building next to the street is not dirty as all of mine were.

The Roof Cleaning Institute Of America Training & Certification Forum "Find A Certified Roof Cleaner Directory"

The Roof Cleaning Institute Of America Training & Certification Forum
"Find A Certified Roof Cleaner Directory"