What % Bleach & How Much Soap?

We get the same question over and over...What percent of bleach should I use on each surface and how much soap do I need to use?

Well of course your asking..This stuff is super confusing when you are just starting out! Lets take a minute to break some of this down for you! 

When this question is asked there seems to be a few more that come up at the same.

  • How do I know what chemical to use?
  • How do I apply it to the surface?
  • How long do I let it dwell?
  • Where do I get all this stuff?

Well, you came to the right place to find a boatload of information. 

The % of Bleach that you should be using depends on 2 things. The first thing to consider is what type of surface are you applying it to and the second point to consider is the surrounding area.

If the surface is super dirty or has been neglected you may need to use a stronger mix...However, often 2 applications of a weaker mix is just as good as one strong application, plus this method will reduce the risk of using to hot of a mix and potentially damaging something. Here is an example...

If you were applying a 6% mix of chlorine to an asphalt roof there is a chance that the runoff could splash onto the outside face of the aluminum gutters and oxidize them. After all, chlorine is an oxidizer. So instead, you may consider using 2 applications of a 3% mix instead. This will do a good job on the roof and greatly reduce the risk of causing damage to the gutters, vegitation or any other sensitive areas around the property. Trust us, the list of things that can instantly get damaged by even the most experienced washers is a very long list and most of the time the only way to restore the item is to replace it. Since we are all here to either make or save money or both, you may want to consider using 2 applications of 3% when you are first starting out. When you are roof washing it is always a good idea to have a "ground person" keeping plants and other areas wet plus moving around small tarps to avoid damage from over spray. Now, let’s give you a straight to the point description of percentages to use. Keep in mind that these are guidelines and every geographical area will slightly differ. 

Asphalt Roof Soft Washing (Based on WEST Coast of Canada & Washington USA)

Extreme algae & moss covered roofs ( North, East & West Sides) 5-6% 

Moderately algae & moss covered roofs ( North, East & West Sides) 3-4%

Asphalt Roof Soft Washing (Based on EAST Coast of Canada & USA plus near the Great Lakes)

Extreme algae & moss covered roofs ( North, East & West Sides) 4-6% 

Moderately algae & moss covered roofs ( North, East & West Sides) 2-4%

**If the south facing sides are looking good, its still a good idea to splash it with a 2% mix so that everything gets a soft wash at the same time. 

Make sure to repeat the roof spray every 3-5 years. We call this a "Spray To Maintain" and you will want to use a 2-3% mixture to keep the organic growth from growing back. This is a great way to keep earning money, check up on the roof and also deliver a fool proof roof maintenance plan for your customers. While you are up there, have a look around and alert your customer if you see something that does not look right. If you know how to fix the issue than offer it to them as an add on service or at least have a handy man or roofer you can refer them to. This is how we build lasting relationships with our great customers who are dying to pay you to make their life easier and more organized. 

Vinyl Siding is another area that needs to be sprayed with a mix, allowed to dwell and then rinsed off. If its covered in algae or any type of "Organic" growth then you will need to use Bleach and a surfactant. For this, the general rule of thumb is to hit it with a 1.5 - 2% mix. 

How do I get a % dialled in like that? Well, there is no short answer but we will do our best here and hopefully expand more on the topic on other blogs. 

Bleach is also known as Chlorine or Sodium Hypochlorite but the cool kids just call it SH. When you call up your SH dealer and they deliver it to you it will most likely and hopefully show up to you as 12.5% SH. Chances are you will have a drum of it and no matter how big or small the drum is the truth is that if you were to pour half of it out and fill it back up with water you would now have a 50/50 mix. Half of the drum would be SH and the other half would be water. So the new % would be 6.25%. You tracking with me? 

Since nobody says 6.25% unless your a psychopath, you just say "I got a 6% mix"

We actually created a calculator HERE that you can use to easily figure out exactly how much water & bleach to mix together to get whatever % you need. Its called a "Batch Mixing Calculator"  

Now, if you had a bucket that had 25% (12.% SH) & 75% water in it you would say that you had a 3% mix of bleach. Why? Well, cause 25% of 12 is 3 of course!! 

Here is a cheat code if you want to clean houses in your town & most of them are vinyl siding and have some algae on them... Buy yourself a:

  1. Downstream Injector (Must)
  2. Injector Bypass (Pretty much a must)
  3. JROD w/ Nozzles (Must)
  4. Ball Valve Bundle (Thank us later)
  5. Bleach (Must)
  6. Apple Grip (Must)
  7. EBC Glide (Thank us later)

How do I apply it to the surface?

Downstreaming will automatically give you a 10:1 ratio and will turn your bucket of 12.5 % into 1.25% but again we just say 1.5% since its actually very accurate. 

You can also use a very popular product called an X-Jet to softwash with your pressure washer and it can give you a 3-4% mix which is often needed when cleaning more stubborn areas like stucco and brick. 

1.5% - 2% is the most common strength to use to clean many areas such as:

Vinyl Siding, Vinyl Decks, Metal Railings, Vinyl Awnings, Aluminum Gutters, Hardy Plank, Painted Wood Siding, Soffits, Garage Doors, Wooden Fences, Metal Flashing, Fascia Boards, Windows, Window Frames, Vinyl Tents plus literally so much more.

When downstreaming or X-Jetting onto a vertical surface you will want to use 2 - 4oz of surfactant (per 5 gallons of mix) to help the SH dwell/cling for a longer period of time. However, if you use to much soap it will:

  • Be a waste of money
  • Take longer to rinse off
  • Increase the chance of windows streaking
  • Increase the chance of the mix sticking to plants and hurting or killing them.. 
  • Increase global warming and have greta yell at you, plus Trudeau will prolly make you pay him more carbon tax…hahaha 

Areas like Concrete Walls, Driveways & Stucco Siding you will want to use a 3% - 4% mix. So you will need to use the X-Jet, a Soft-Wash System that Batch Mixes or Proportions via a Blend Manifold

Sooo many links to click on........ Well…now that you have added $10,000 worth of stuff to your cart and maxed out your credit card, just hang tight because first we need to answer some other burning questions! 

How do I know what chemical to use?

Well, lets break it down into 3 groups... and in a future blog we will explain in way more detail... We promise...

If its ORGANIC we want to use BLEACH...Dont over think it. But like we said we will shed some light on a few other products that can be used as well in another blog post…

Organic means it grew there naturally. So stuff like algae, moss, lichen, tannin plus way more stuff. (leave a comment about the crazy stuff you have growing where you live) 

If its greasy or oily you will want to use a DEGREASER...

Often you will want to remove all of the organic matter first and then attack the greasy stuff after. You can also add degreaser to your SH and apply it to the surface before pressure washing it off. Just make sure to use the mix that day or soon after so the degreaser does not have time to weaken the strength of the SH. (never mix chlorine & acid together) 

If its greasy like food grease you will want to use a caustic degreaser... We like Agent Groundforce

For all other oil stains we highly recommend using EBC Degreaser. (Works good for BBQs too)

If its INORGANIC like Rust, Fertilizer Stains or Effloresence you will want to use some type of ACID...

We have every type of soap and chemical you could think of to tackle almost any restoration job. Search through our Soaps & Chemicals to get more familiar or contact the store to get a rundown. 


How long do I let it dwell on the surface before I remove it?

This one is hard to answer because each stain will require a different amount of time. But a good starting point is as follows...

1.5% - 2% mix while doing a house wash on vinyl or on the long list of areas this mix will work on is about 10 minutes. People will tell you to "Keep the area wet" but its not true. If you use the proper % and the right amount of soap you can let it sit overnight then come back and rinse it off easily. You will rarely ever do this but dammit if you wanted to you could...

When spraying a roof with a 6% mix we suggest you leave it on the shingles FOREVER...Thats right...FOREVER… Spit that mix and let mother nature rinse it off. Of course we highly recommend to brush all the moss of first, leaf blow the roof, clean out the gutters and then install Gutter Baskets and finally...Spray the roof…but don't forget  to collect your cheque! 

Oil stains should get good results using 20:1 and even 40:1 ratios. Cold water pressure washers work just fine when you use the commercial grade degreasers that come from EBC, F9, Eaco Chem, Agent Clean and Gold Assassin…shameless plugs, we know...we carry them all right here in Canada and can ship them to you fast.. Try Us!!!

Hot water pressure washers will get the job done slightly better and much faster so you should use heat if you got it! The typicall dwell time for an oil stain is about 15 minutes and sometimes 2 applications are needed. To really knock it out of the park, you can apply a product called F9 Groundskeeper to the area after you have cleaned it your very best. It will shave another small layer off the surface of the stain. Considering even the best of us often leave an "Oil Shadow" behind since concrete is very porous, make sure to always tell the customer ahead of time that it will look much better but it will most likely not be perfect. Continue on and tell them that the slip & trip hazard will be gone and that the oil stain will look the best that it can because you got all of your high end soaps and chemicals from BIG SHOT SUPPLIES CANADA...Which bring us to our next point...


Where do I get all this stuff?

Seriously?? You know where. 







  • Thank you !

  • What mix and strength would you use to post-treat concrete?

    Dylan Byrne

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