Jump to content
Fast Finish

To Rinse or Not...

Recommended Posts

I see a lot of threads regarding a lot of rinsing and then rinsing some more. With all the real thick moss how soon do you"have" to rinse? Can you leave it on there and come back in a day or two or even a week with no problems? I know there are more states than just Oregon and Washington that grow their grass on the roof...

Will it damage gutters or even worse by leaving it to do the job?  Can you ever get away with not rinsing at all?  Specifically in then wet states NW?  I am using a 30% mix starting out.  

Share this post


Link to post
Share on other sites

no rinse for us... even without gutters.... in that situation we water a lot! but then the only thing that will rinse the roof is the rain, which will dilute the mix for us.

Share this post


Link to post
Share on other sites

no rinse for us... even without gutters.... in that situation we water a lot! but then the only thing that will rinse the roof is the rain, which will dilute the mix for us.

You better HOPE it does! Because it usually does, but a 1/2 ass rain can mess up all your good intentions! A 1/2 ass rain can cause all the salt left on a roof to come off, w/o enough dilution to render it harmless. Grass and plants can be burned, and even killed! 

Be aware of this JC, I would hate to hear a customer choked you out brother, for killing their yard.

A good 'compromise' is to rinse the bottom 1/3 of the roof, from the ground with a water hose.

This way, if u do get a 1/2 ass rain, there is not enough salt left up there to do chit to the yard.

 

Also, since I am 'preaching' , be sure and use a 3/4 inch mean green water hose, from factory direct hose Guys.

All that extra water the larger 3/4 diameter provides over standard garden hose will greatly aid you in plant watering.

Share this post


Link to post
Share on other sites

In my service area we have moss and lichen on every roof and basically no rain for 5 months. Having said that:

Rinsing:

Pro's: it definitely looks better rinsed.

You won't have to worry about a "1/2 ass rain" which will fill the soil with salt but not dilute.

You don't have to flush the gutters since this will be done with the rinse. We always rinse/flush all metal since the large amount of

Salt leftover is corrosive. (We mention this in our proposal so they know we care for their property and understand how to

Properly protect it, even though most likely they would have had no idea)

Con's: It takes longer. It's not just a rinse, it's also a salt dilution.

You lose the residual effect of leaving the dried chems on the roof, it's not the SH (that's dead) its the salt, which crystalizes and breaks down

the structure of moss and lichen.

Sometimes you will have copious bubble overflow at the downspouts and usually more clean up because of the fines and moss that

Wash off the roof.

Fast Finish: The northwest is unique. Unfortunately you can't clean roofs the way most of the guys on this forum can. If you apply your solution you are going to oxidize all that moss which will look much worse than when you started, telling the HO it will go away with wind and rain is simply not the case and they would not be happy with the job even if it did (cuz it will look like snow). Also, you have to use much more solution so the large moss fluff soaks up enough to get to the tendrils. Gutter cleaning is an extra service for homes that only have GM. For roofs that have moss it has to be part of the service. Without the proper method you will have to do it twice.

I have a method that works great if you want to pm or call. This info will only cost you $49,999.99. I will also include an official "Pacific Roof Cleaning" Sticker.

Just kidding. Give me a buzz if you'd like. It's pretty simple and effective.

BTW, The 'Mean Blue' hose is decent too.

Share this post


Link to post
Share on other sites

If no gutters, with the plant roots flooded-preferably to the point of standing water,I tarp the plants, then rinse the roof. Otherwise, like Chris said, a small rain and you have a salt soup all over the plants!

If the roof it too high to rinse it all, I do as Chris said and rinse the bottom 3rd or all I can get to.

In this situation, you may put as much effort into plant care, as into the roof cleaning!

Some jobs without gutters, I just pass up. I prefer to sleep at night.

Share this post


Link to post
Share on other sites

I am selling my customers a system where I come back in 30-60 days to inspect roof and touch up for those really difficult overgrown areas. It rains so much here that rinsing off ( on the over burdened roof) seems like a guarantee to spray again anyway to get down to the roots. I am sure I will rinse 75% of the time, as I don't want to leave a white salty roof behind. But on the thick stuff I have to I think.

I am also charging a premium so coming back isn't a burden to the program and it gets me in front of the customer for our other services we do..

Share this post


Link to post
Share on other sites

In my service area we have moss and lichen on every roof and basically no rain for 5 months. Having said that:

Rinsing:

Pro's: it definitely looks better rinsed.

You won't have to worry about a "1/2 ass rain" which will fill the soil with salt but not dilute.

You don't have to flush the gutters since this will be done with the rinse. We always rinse/flush all metal since the large amount of

Salt leftover is corrosive. (We mention this in our proposal so they know we care for their property and understand how to

Properly protect it, even though most likely they would have had no idea)

Con's: It takes longer. It's not just a rinse, it's also a salt dilution.

You lose the residual effect of leaving the dried chems on the roof, it's not the SH (that's dead) its the salt, which crystalizes and breaks down

the structure of moss and lichen.

Sometimes you will have copious bubble overflow at the downspouts and usually more clean up because of the fines and moss that

Wash off the roof.

Fast Finish: The northwest is unique. Unfortunately you can't clean roofs the way most of the guys on this forum can. If you apply your solution you are going to oxidize all that moss which will look much worse than when you started, telling the HO it will go away with wind and rain is simply not the case and they would not be happy with the job even if it did (cuz it will look like snow). Also, you have to use much more solution so the large moss fluff soaks up enough to get to the tendrils. Gutter cleaning is an extra service for homes that only have GM. For roofs that have moss it has to be part of the service. Without the proper method you will have to do it twice.

I have a method that works great if you want to pm or call. This info will only cost you $49,999.99. I will also include an official "Pacific Roof Cleaning" Sticker.

Just kidding. Give me a buzz if you'd like. It's pretty simple and effective.

BTW, The 'Mean Blue' hose is decent too.

This post was the one I have been looking for....very informative and helpful being new to roofs. We pay close attention to details and you provided what I needed to at least get into more jobs. I would also like three of the official roof cleaning stickers... Where do I send the check?

Share this post


Link to post
Share on other sites

In my service area we have moss and lichen on every roof and basically no rain for 5 months. Having said that:

Rinsing:

Pro's: it definitely looks better rinsed.

You won't have to worry about a "1/2 ass rain" which will fill the soil with salt but not dilute.

You don't have to flush the gutters since this will be done with the rinse. We always rinse/flush all metal since the large amount of

Salt leftover is corrosive. (We mention this in our proposal so they know we care for their property and understand how to

Properly protect it, even though most likely they would have had no idea)

Con's: It takes longer. It's not just a rinse, it's also a salt dilution.

You lose the residual effect of leaving the dried chems on the roof, it's not the SH (that's dead) its the salt, which crystalizes and breaks down

the structure of moss and lichen.

Sometimes you will have copious bubble overflow at the downspouts and usually more clean up because of the fines and moss that

Wash off the roof.

Fast Finish: The northwest is unique. Unfortunately you can't clean roofs the way most of the guys on this forum can. If you apply your solution you are going to oxidize all that moss which will look much worse than when you started, telling the HO it will go away with wind and rain is simply not the case and they would not be happy with the job even if it did (cuz it will look like snow). Also, you have to use much more solution so the large moss fluff soaks up enough to get to the tendrils. Gutter cleaning is an extra service for homes that only have GM. For roofs that have moss it has to be part of the service. Without the proper method you will have to do it twice.

I have a method that works great if you want to pm or call. This info will only cost you $49,999.99. I will also include an official "Pacific Roof Cleaning" Sticker.

Just kidding. Give me a buzz if you'd like. It's pretty simple and effective.

BTW, The 'Mean Blue' hose is decent too.

 

ahh i came across this a long time ago i remember when i started out.  This is very very true, never leave moss on the roof, ever.  It will NEVER go away by nature.  It's a job in itself to remove it, and can be very tricky.  We deal with it on EVERY roof we do up here in B.C Canada.  Sometimes we have to use handbrushes, puddy knives, rinsing, etc.  Also, it needs another treatment.  Zinc sulphate @ 35.5%.  It's like flour and it sticks to roofs and creates a barrier for a year.  Apply it after the roof is completely clean.  The moss won't come back for a very very long time.  It's also cheap and goes a long way.  But yes, you must remove it.  I am interested in seeing what you do, may give you a shout sir

Share this post


Link to post
Share on other sites

We have the same issues to a lesser extent, we leave it crystalized on the roof and explain to the Homeowner the reasoning for it. The longer it stays on the better it works, we also tell them we ALWAYS do a follow up 30 days later and retreat as needed. If you manage your customers expectations from the start life is much easier.. So far we have had no problems collecting a check and only had to go touch up two roofs, if the H.O. wanted to be adamant about not paying till it was rain rinsed to their satisfaction, I'd have no problem with that either. Customer service is King, especially when its an Angies Lister.. Lol.

Share this post


Link to post
Share on other sites

The last couple jobs ended up being a no rinse with almost 50% mix. The pitch was super steep and it wouldn't rinse off with a soft wash set up.   Short of dangling from a string on a bucket with a brush or a pressure washer to nudge it.... We rinsed some areas that wanted to move, and it set long enough. Checking back on the job as we always do with the customer.

Share this post


Link to post
Share on other sites

ahh i came across this a long time ago i remember when i started out.  This is very very true, never leave moss on the roof, ever.  It will NEVER go away by nature.  It's a job in itself to remove it, and can be very tricky.  We deal with it on EVERY roof we do up here in B.C Canada.  Sometimes we have to use handbrushes, puddy knives, rinsing, etc.  Also, it needs another treatment.  Zinc sulphate @ 35.5%.  It's like flour and it sticks to roofs and creates a barrier for a year.  Apply it after the roof is completely clean.  The moss won't come back for a very very long time.  It's also cheap and goes a long way.  But yes, you must remove it.  I am interested in seeing what you do, may give you a shout sir

For those who have not seen this information about Moss Control on Roofs, here it is.

Forget the zinc and copper strips for roof moss prevention, they don't work.

 

Chemical Moss Control for Roofs, Decks, and Sidewalks

 

Zinc Strips

img31.gifGeneral Information: Zinc strips are usually considered the long-term solution to controlling mosses (see photo at right: skylights are surrounded by galvanized flashing that has suppressed the growth of mosses below the skylights. The remaining parts of this cedar shake roof are covered mainly with the moss Dicranoweisia.  Zinc strips and galvanized flashing are apparently relatively safe and inexpensive. They effectively kill or retard the growth of mosses and fungi and appear to have effect up to 15 feet below the zinc flashing along the length of the flashing.  To use: apply the rolled zinc or galvanized flashing to each side of ridge caps along the roof peaks.  Place a nail down each foot of the zinc strip.  With each rain zinc is released from the strip and kills the mosses below the strip.  For best results remove the existing mosses prior to treatment. The active ingredient is metallic zinc.

Effectiveness: Zinc strips are considered to be effective for up to one year for most brands.  The effect of galvanized flashing (example above) can persist for decades. Success rates vary with the degree of moss development and weather.  Zinc strips or flashing are most effective before mosses are well developed. Physical removal of existing moss followed by installation of zinc strips or flashing is an effective long-term strategy for suppressing moss growth.

Negative Side Effects: Direct runoff from the zinc strips or flashing to surrounding vegetation, fish ponds, or water supplies should be avoided, because some contamination by zinc is likely to occur. Zinc strips should not be used with strong acids or bases.  

Possible Alternatives: Consider periodic physical control.

Potassium salts of fatty acids

General Information: This product is non-staining on most surfaces and is for use on decks, fences, roofs and lawns. This product will not harm bordering plants. This kind of moss killer is formed from naturally occurring, biodegradable fatty acids.  It is water based non-corrosive to metals and contains no zinc or iron. This product is available in liquid form in several brands. One brand is Safer Brand for moss and algae.  To apply this product, attach bottle to hose and spray liberally over infected area.

Effectiveness: Many people have reported varying degrees of success with the use of potassium salt products.  Experimental trials on Racomitrium on old asphalt resulted in very little kill, even at concentrations well above the recommended dose (Ash 1999).

Negative Side Effects: Because this product occurs naturally in the environment and is biodegradable the environmental side effects are small. This product is toxic to aquatic invertebrates.  Potassium should not be applied directly to water and should not come into contact with water sources.  

Possible Alternatives: Before treating mosses one should consider whether it is necessary to treat the mosses or not. Please see our site on whether or not to control mosses as well as the page related to applying bleach to mosses. 

Zinc Sulfate

General Information: The active ingredient for some moss killers is zinc sulfate monohydrate usually at concentrations of 99%.  One brand name is Moss B Ware. Zinc sulfate will not stain roofs or corrode aluminum and galvanized gutters.  To use zinc sulfate one can apply powder directly to moss areas.  Manufacturers recommend that powder should be applied thoroughly  - for example, up to three pounds for every 600 square feet.  For spraying combine three pounds to five gallons of water and apply to 600 square feet.  This product needs to be applied on a calm day.     

Effectiveness: Powder application has been known to control mosses for two years and spraying application may need to be applied annually. Some roofing companies will guarantee no mosses for up to five years after using this product while treating roofs.  

Negative Side Effects: This product is toxic both to fishes and aquatic invertebrates.  Zinc sulfate should not be applied to water.  If zinc sulfate comes into contact with neighboring plants, damage may occur.  Plants and shrubbery should be draped when this chemical is being used.

Possible Alternatives: Though this product is effective in controlling mosses, it is not entirely environmentally safe or smart.  Conside the need to control -- is there a different perspective or solution to your moss problem without polluting the environment?

Zinc Chloride

General Information: Zinc chloride comes in two different concentrations, 13% and 62%.  The 13% concentration can be applied directly to moss without mixing with water. Spray directly from nozzle six to ten inches away from target. Make sure to wet the area thoroughly. The 62% concentration needs to be mixed with water before applying to an affected area. Mix one pint of concentration to three gallons of water.  Using a backpack sprayer, one manufacture recommends using one gallon for every 100 sq ft. Zinc chloride should be applied just prior to fall rains or in the early spring.

Effectiveness: Zinc chloride is effective in controlling mosses from one year up to five years.  Increased application concentrations may be needed in areas of higher moss concentration. 

Negative Side Effects: Avoid drift and runoff when using this product.  Zinc chloride will affect other plants and lawns. Application should only take place when air is still and when no rain is expected within 24 hours. Zinc chloride is corrosive and should not be used when copper fixtures are present.  This product is toxic to fishes and aquatic invertebrates. Avoid contaminating water sources with zinc chloride.  If zinc chloride comes into contact with a painted area damage is possible.   

Possible Alternatives: Considering the toxicity of this chemical, it may be possible to use a less corrosive and less dangerous product.  Please see other chemicals on this web site as well as considering reasons to control or not.

Zinc - Copper sulfate mix

General Information: Zinc and copper sulfate comes dry, but can be applied as a powder or mixed with water.  This product reacts electrolyticallly with water to stimulate a slow release reaction.  Zinc and copper sulfate will not stain patios, decks, walls, walkways, buildings or roofs.  However, zinc and copper sulfate may react with red bricks.  This product is not harmful to lawns, ornamental shrubs, trees, turf or other vegetation such as flowers and vegetation.  To apply simply sprinkle areas thoroughly with powder when it is wet, either after a rain or when early morning dew is present.  Do not use this product in high wind. For spray application a wet applicator may need to be purchased. It is not clear if this product is still available commercially. According to information from one manufacturer, apply one pound of moss killer to 1000 sq ft.  This product may be applied anytime during the year, but should not be applied while it is raining.  Since this product specializes in the slow release reaction; allow plenty of time for the chemical to act. This product is corrosive and should not be used if copper fixtures are present.

Effectiveness: Applications of zinc and copper sulfate are said to last for up to one year depending on the concentrations of moss.  Annual application is generally needed.

Negative Side Effects: Though this product is supposedly safe for surrounding plants, it is toxic to fishes and aquatic invertebrates.  Do not apply this product to water or let the product come into contact with water sources.  When applying this product or any product to rooftops it is essential to avoid runoff. Collecting the runoff in a fashioned trap would greatly reduce the negative effects on the environment.  

Possible Alternatives: Based on the manufacturer's information, this chemical would seem to be a slightly better chemical to use when considering the environment. Considering the components, however, leads us to doubt this. See the section on zinc sulfate above. The toxicity of copper sulfate is well known. Deciding whether or not to control is still a good question to consider.

Bleach

General Information: Chlorine bleach (sodium hypochlorite) can be used on a number of surfaces contaminated with mosses including decks, patios, walks and roofs.  When used to proper concentrations bleach is non corrosive to metals and will not stain treated areas.  One should, however, avoid contact with clothing.  Brand names of bleach especially for mosses can be found in the moss control area in garden centers - one brand is 30seconds brand.  To apply bleach mix one part water with one part concentrate.  Use a backpack sprayer and spray liquid to dry area infected with mosses.  Keep surface wet for at lease 30 seconds.  After finishing application rinse thoroughly with water. If applying to wood keep wet for at least 15 minutes.  An alternative to this concentration is to use four times the water.  When applying one will need to keep the surface wet for four times as long.  This concentration will cover 600 sq ft on porous surfaces or 1800 sq ft on non-porous surfaces.  

Effectiveness: Bleach applications remain effective for up to one year, but annual applications are usually necessary.

Negative Side Effects: Bleach at these concentrations will be toxic to plants if left on for more than ten minutes.  After ten minutes, injury or "burning" of foliage will occur.  Since this product is toxic to fishes and aquatic invertebrates contact with water sources should be avoided. 

Possible Alternatives: Bleach is a good alternative to many other chemical controls, being less toxic to plants and aquatic ecosystems.  Additionally, one could consider not controlling the mosses at all. 

barbwire.JPG

Share this post


Link to post
Share on other sites

Yeah chris we use zinc sulphate 35.5% concentration... can be bought in 50 lb bags at feed stores for 60 bucks... it's really cheap and keeps the moss away much longer then a year, also aids in keeping the algae away much longer also.  Probably the best preventative i have come across yet

Share this post


Link to post
Share on other sites

The AMRA (American Manufactures Roofing Association) and GAF (the largest maker of shingles) recommends a mixture of bleach, TSP, and soap. Bleach is perfectly safe to use, unless you are trying to sell a product. Most companies that are trying to "scare" us not to use bleach are simply pushing their products. It's basic marketing. The products they are selling contain sodium hydroxide. For those of you who don't know, Sodium hydroxide  is a caustic lye and a "very" powerful de greaser. Oh yes, I should mention that your shingles hold the granules on with tar. Tar is a oil "grease" product.

I own a professional roof cleaning business in Tampa Florida, and use bleach safely and with instant success. Of course care should be used. You would never just spray bleach on your plants, take the time to water them before, during and after, and you will have no problems. The ions in the sodium hypoclorite begin to break down upon contact with an organic material (mold/fungus). I'm not pitching a product, I just want you to be well informed about roof cleaning chemicals.

Share this post


Link to post
Share on other sites

An interesting thread as this was one question I was going to ask.  Here in the UK moss is a huge problem on a lot of roofs, some look like they have a green carpet over them.  Will "Soft Washing" remove the moss or does the moss have to be removed by hand then "Soft washed"?

 

Most newish homes aren't too bad, my house is 8 years old and has, black algae, yellow lichen and some moss.  

 

Most people who have bad roofs that will require cleaning in the UK will have moss on them, I'm I wrong to assume that "Soft washing" is a silver bullet that will rid it all.

 

I'd rather find out now before investing in a system.  Nearly all the roof cleaning guys in the UK I can find pressure wash roofs...

 

If anyone can enlighten me on the full process of cleaning a roof with a heavy moss build up I'd be most grateful.

 

Thanks in advance

Jonathan

Share this post


Link to post
Share on other sites

Green moss and lichen will die when sprayed with roof cleaning solution. Moss will turn white and look like cotton balls. Since moss and lichen grow active roots down into the shingle, it is better to let the roots dry out and break off, which may take several weeks of sun. Trying to remove these growths early can result in damage to the roof. Most will come off on their own in the first heavy rain. Just explain the reasons and check back with them in a couple of weeks.

Share this post


Link to post
Share on other sites

We rinse. The SH breaks down the Lignin in the moss root structure making it easier to get off. Moss that isn't strongly anchored in will come off with a high volume rinse. Anything which doesn't come off after the initial rinse is dead so it is left to further decay. Customer has the option to leave it (it WILL come off with the snow in the winter) or have us come back out after a few weeks to do a second rinse down. Most leave it and next season....gone.

The key to the moss is dwell time with your SH. We wait about 20 minutes between application and rinse.

As for Zinc Sulphate, it works but plant protection is still important and you NEED to know where your runoff goes to avoid killing the critters. Have thought about mounting a small third tank I have sitting here with a little 3/8" All Flow I have in the warehouse as a sulphate tank. Would be good as a pre treatment for the really bad houses.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...