Go Back  The Hull Truth - Boating and Fishing Forum > BOATING FORUMS > Dockside Chat
Reload this Page >

Streaks/stains on roof shingles - cleaning/preventing??


Streaks/stains on roof shingles - cleaning/preventing??

Old 06-01-2010, 08:01 AM
Senior Member
Thread Starter
Join Date: Jul 2006
Location: DE
Posts: 2,106
Default Streaks/stains on roof shingles - cleaning/preventing??

Was reading the pressure washer thread and it got me thinking about the black streaking on my roof shingles. The streaking/staining is mostly on the north side which makes me believe this is some sort of mold/mildew condition.
I have seen advertisements for guys who will come out and clean these off. Does anyone know what they are using and how they apply it?
I suspect a pressure washer is not a good idea as it will damage the shingles. Maybe some bleach/cleaner solutiuon from a garden sprayer (and a rope and harness to keep me from falling off the 8/12 pitch)
My shingles are 12 or 13 years old slate gray colored, 40 yr architectual type. Any advice on cleaning the streaks or preventing reoccurrence would be appreciated.
starmonk is offline  
Old 06-01-2010, 08:11 AM
Senior MemberCaptains Club Member
Join Date: Jun 2001
Location: CT
Posts: 18,362

I have used a garden sprayer with 50% clorox on my asphalt slate colored shingles and vinyl siding and it worked fine - do a test area first to make sure you don't bleach out the color.

If possible I would just use a graden sprayer from the sides (ladder) if possible and do as far as you can with the spray and maybe garden hose pressure - Just so you don't have to walk on the roof (my roof lines are such that I can do it this way where it gets moldy).
LI Sound Grunt is offline  
Old 06-01-2010, 08:17 AM
Join Date: Dec 2009
Location: Texarkana, AR
Posts: 72

I was just in Lowes yesterday and saw that they had a shingle cleaner that you attach to your garden hose. It was located in the section where the deck wash and deck stain was. I don't remember the brand name, but I do remember that it said that it was used to remove the black stains from shingles and mildew. Hope that helps some.
COLINMC is offline  
Old 06-01-2010, 10:22 AM
Senior MemberCaptains Club Member
Join Date: Aug 2002
Location: S. Galvez, Louisiana. Ame
Posts: 7,448

Best cure I found yet--- quit looking up!
twentynine is offline  
Old 06-01-2010, 12:05 PM
Senior Member
Join Date: Nov 2008
Posts: 864

Pro power washers are not going to give away our formulas but you can get away with 12% bleach and Dawn dishwashing soap mixed with water. BTW we use low pressure and downstream the solutions.
MarlynOC is offline  
Old 06-01-2010, 01:31 PM
Admirals Club Admiral's Club Member
Join Date: May 2010
Posts: 85

Check this site out....I bought some stuff from them and it's working great

duboisdl is offline  
Old 06-01-2010, 03:15 PM
Admirals Club Admiral's Club Member
Join Date: Feb 2010
Location: Land O Lakes, FL
Posts: 3,523

There are many products on the market that claim to clean shingle roofs. Most will not clean the roof by themself. Most will require you to use some pressure to remove the mold, algea, mildew, etc.. You can safely pressure clean a shingle roof if your machine is capable of allowing you to adjust the pressure. You do not want to get up there with a 3500 psi machine running full blast. Most "pro" companies that advertise low pressure roof cleaning are pumping straight chlorine on the roof, the better ones will have a guy on the ground spraying a neutralizer on the stuff running off the roof and on the grass and bushes. However in most cases, in about a weeks time you will have a ring around your house from all the plants and grass that were killed. That said, using chlorine is the cheapest, easiest and fastest way to make the roof look clean. In a situation like yours, with a steep pitch, you may not have a lot of options. Whatever chemical you use, I would recomend rinsing the roof with fresh water after your done. I have come behind the chlorine guys a year or so later and have seen the front edge of all the shingles curled up from the chlorine drying them out. We have also cleaned a roof on one house using a "shingle roof cleaner" followed by a light pressure cleaning during the same week as the neighbor had his roof chemically (chlorine) cleaned and ours stayed looking clean for 3 years, his needed to be done again after 1 year.
Its better to kill it and remove it than kill it and leave it. If you do hire someone, dont fall for the warranty scam.
Jonesy23 is offline  
Old 06-02-2010, 05:05 AM
Senior MemberCaptains Club Member
Join Date: Dec 2007
Posts: 15,725

Jonesy23, does adding Jomex to the Clorox/water mix limit or prevent vegetation death?
bamaboy473 is offline  
Old 06-02-2010, 07:05 AM
Senior MemberCaptains Club Member
Garett's Avatar
Join Date: Feb 2003
Posts: 24,220

Originally Posted by bamaboy473 View Post
Jonesy23, does adding Jomex to the Clorox/water mix limit or prevent vegetation death?
Diluting down the drip line with a good soaking from a garden hose should take care of any die off issues.
Garett is offline  
Old 06-02-2010, 03:02 PM
Admirals Club Admiral's Club Member
Join Date: May 2009
Location: Crosby, Texas
Posts: 1,709

You probably noticed that the shingles don't stain underneath your roof jacks that are either galvanized or lead. That's because zinc oxide washes off of them when it rains and zinc oxide kills mold/mildew. Long thin strips of galvanized metal are available that tuck partially under the tabs so when it rains it washes the zinc oxide down your roof and kills the mold.

As I also noted on the pressure washer thread don't overlook http://wetandforget.com/. It really does work for keeping off the mold for a year or two.
HTV is offline  
Old 06-02-2010, 03:45 PM
Senior Member
Join Date: Apr 2009
Location: 26 46' 18.72"N 80 02' 47.34"W
Posts: 2,757

1- Do not use any pressure on a shingle roof....DO NOT!
2- Avoid using bleach or chlorine.

There are environmently friendly shingle cleaners out there, call you local roofing supply company and they will help you.

ABC Supply and Bradco Supply are a few larger ones.

Last edited by Cmann; 06-02-2010 at 03:59 PM.
Cmann is offline  
Old 06-02-2010, 06:37 PM
Admirals Club Admiral's Club Member
Join Date: Feb 2010
Location: Land O Lakes, FL
Posts: 3,523

I am not 100% on what Jomax is, is that the home depot stuff? Do not mix any other chemicals with bleach except soap. By "pressure" washing the roof, I am talking about using about 1200 psi with a 40 deg spray nozzle, not much more pressure than a nozzle on a garden hose or a hard rain storm. If you think about the idea of a chemical strong enough to eat away and kill mold, algea and mildew, how environmentaly friendly is it? If its strong enough to kill the living organisms that show the black streaks what makes you think it will not kill other living things in the enviroment? I have seen the galvanized strips installed on a couple roofs, they look sort of silly and you would have to run them every 4 to 5 feet going up the roof and the entire length of the roof. I have not tried every chemical on the market so there may be one that works better than the rest. Given the pitch of the roof, if it was my house, I would run the sprinklers on the grass, cover the plants, mix up a 50/50 solution of chlorine/water spray it with a pump garden sprayer, wait about 20 minutes then rinse with fresh water and a chlorine neutralizer and call it a day. Others may choose to spend all day and a $100 dollars on chemicals that may or may not get it clean, kill the plants, hurt the roof, etc..
Jonesy23 is offline  
Old 06-03-2010, 04:15 AM
Senior Member
Join Date: Apr 2009
Location: 26 46' 18.72"N 80 02' 47.34"W
Posts: 2,757


( I have no affiliation to this product or company. )
Cmann is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off

Thread Tools
Search this Thread