Gutter outside cleaning (whitening)

Hey guy

Quick question; when you have to clean the outside of the gutters what kind of brush do you use ? I’ve done only a couple of jobs and took forever to have 'em looking brand new (premium price, premium service right? ), using a extension pole with a soft bristle brush just to be on the safe side and try to not damage the paint with a hard bristle brush. The one I’m using is a cheap one, no brand name, bought at Big Lots and pretty much disposable (one job use), and this thing looses its shape after the first hour of use.
I’m using F13 from Pressure Tek which works wonders.


Try guttter zap and the will look brand new very quikly without hardly any effort.

How do you apply?

We spray it on with a garden sprayer and let it sit for just a bit, then we go over it with a soft brush, then spray off.

Paint on the gutters or the house siding? If the outside of the gutters have been painted, ( I see it occasionally) I’m not sure gutter zap or F13 would be the best chem for the job.

Puntadigital, you’re using F-13 which is a really great gutter whitener so you’ve got the right chemical, although there are others that work just as well.

Those cheap (stiff bristle) brushes that can be bought at Lowe’s are not the best for the job. You can find really nice soft to medium soft “Truck” style brushes at most any RV/Camper center.

The brushes that have a much higher count of bristles will probably hold and release (onto the gutter) the chemical better than the cheap low count bristle brushes.

Here’s here’s a great way to apply the F-13 with a brush on an extension pole:

Mix water and F-13 in a 32 oz. spray bottle at an 8:1 ratio. Place the bottle in a bottle holster on your belt.

Lightly spray the contact area of the brush with just a few pumps of F-13 (or your chemical of choice). Brush the chemical onto about 6 to 10 linear feet of gutter.

Slightly agitate chemical with brush then quicky rinse with a jet nozzle on the end of a garden hose.

Stains will usually be gone with 1st application but sometimes a second application will be needed.

NOTE* The F-13 or chemical of your choice can be mixed stronger so that all of the black streaks will come off with the first application. The downside of this is that more (or even all of the) paint will come off of the gutter along with the dirt. It’s best to start with a weaker solution and then bump up the concentration of chemical only as needed.

I’m very cautious so I stick close to my 8:1 ratio of water/F-13 so I don’t have to buy new gutters for my customers.

Please note that the 8:1 ratio that I use is for F-13 Gutter Grenade. If you are using any other chemical you will need to determine the proper ratio or mix.

Maybe others that use Gutter Zap or other chems will offer their mixes. But the 8:1 ratio is really good for F-13 Gutter Grenade.

In my previous post I explained the method of using a spray bottle to apply the F-13 to the brush.

You can also just mix the F-13 with water in a bucket and just dip your brush into the bucket. The problem with this is the brush is sturated with chemical and is more likely to drip off onto other surfaces before you get the brush up to the gutters.

Also you waste more of the expensive chemical when you use the bucket method.

I’ve used both methods and prefer the spray bottle over the bucket.

Right. The original question was, “What kind of brush do you use?”. Not, “How do you apply F-13?”. But thanks for the lesson. It was informative.

So what brush do you use? You didn’t really specifically say what you use.

Seth, sorry if I offended you. He asked “what kind of brush”, not what brand of brush, so I described the kind of brush that I use and told him where he can find a similar kind of brush.

I don’t actually know what brand of brush I use but I can find out if you’d like.

I tried to answer the original question as well as I could and then offered helpful advice on how to apply the F-13.

When I was looking for a good cleaning method for black streaks on gutter exteriors I ran across the spray bottle/brush method on a pressure washing forum.

I found this method to be very helpful so I offered it to one of our fellow forum members. Just trying to be helpful.

Thanks for the answers you guys.

I’ve considered the spray bottle method myself and as you said you have more control on where you apply it and you don’t waste any of it like in the bucket/brush method. I haven’t done that since you have to move the ladder a lot of times compared with the dipping method that is performed from the ground. That house that I did the other day took me like 5hrs to clean gutters in&out and pressure wash a few brick walls, but my hands REALLY hurt still, since I was fighting with a cheap and flimsy extension pole and a POS brush.
Now I bought a nice Mr Longarm pole aluminum/fiberglass w/ locking mechanism to avoid having a spinning brush.

I’ve used Gutter ZAp and I like it, but the mix ratio is not as good as in the F13, ZAP has to be mixed to 2:1 or even 1:1 sometimes, and since I cannot buy it locally I have to pay for shipping and I HATE to pay shipping on liquid stuff. F13 lasts me longer.

Puntadigital, I probably need to clarify that the method of spraying a small amount of F-13 on the brush method is for cleaning the gutters from the ground with the brush on an extension pole.

I fill the spray bottle with F-13/water mix then put it in a bottle holster on my belt. With the brush still attached to the extension pole just spray a few pumps of F-13 onto the brush then lift the brush up to the gutters from the ground. Brush on F-13 then rinse.

No ladder needed. I use an Ettore 24’ pole instead. A nice comfortable pair of gloves really helps out too.

This is really a great and safe method of cleaning gutters from the ground.

I think you’re right about the F-13 lasting longer and being cheaper to have shipped.

No offense at all. I was just trying to point out that sometimes we all go off on tangents and may not always answer the said question. Sometimes we learn from it sometimes not. I learned from yours.

Very helpful. Thanks.

I’m still curious if Puntadigital meant painted gutters? Do use use the specialized gutter cleaners if the gutters have been painted on the outside? I usually get by with my regular house wash if that is the case.

Nuvudude: Thanks for the clarification and for sure I’ll be trying your method since is really hard to be carrying a 5 gallon bucket around the house, and the dirt that remains in the brush is transfered to the mix when you dip the brush inside the bucket, and I believe that this makes your mix weaker along the way. Thanks for the help.
BTW … where are you located?

Seth : I wasn’t talking about painted gutters, but I’ve read about butyl cleaners like F13 or Gutter Zap used too strong or to often can damage the finish of the gutters, that’s what I was trying to portrait. Sorry for the poor choice of words,is hot and I’m having a beer :smiley:

Seth, All of the gutters that I do have the factory (baked on, I guess) paint that more than likely has a much better bond to the gutter than re-painted gutters.

I would not clean gutters with F-13 if they have been (post factory) re-painted . F-13 or those butyl based cleaners like Gutter Zap would probably just take every bit of that paint right off.

Like you, I would use my house wash and leave it at that. If the customer was still unsatisfied I would tell them that a stronger chemical would probably take the paint off.

If they still wanted me to use the stronger chemicals I would do it only with a signed waiver and be sure that they understood that the gutters may need to be repainted if the old paint comes off.

But if they have been re-painted once I guess it would not be a big deal to the customer to paint them again if they signed the waiver with the understanding that the strong chems may take the paint off.

That would be their call and their responsibility to have the gutters re-painted. I just want to clean their gutters if it can be done without damage. If it can’t…I don’t want to be responsible for the damage.

My main concern with F-13 or the butyl based cleaners is with repeated use on the same gutters. I tell my customers that I wouldn’t use this chemical on their gutters more than every 3 or 4 years…but just how many repeated applications of this stuff (even spaced out 3 or 4 years) before we get down to bare metal?

Got it. I got clarification now. I see occasionally gutters that have been repainted with regular latex paint (cheap easy fix I guess) and wasn’t sure if that’s what we were talkin about.

By the way, I use a soft bristle brush like yours for cleaning the outsides of gutters.

I also use Gutter Zap. :slight_smile:

Puntadigital, I’m in the Southeastern USA.

Yeah, the repeated dipping of the brush into the bucket does weaken the mix. And when you get through you still have a lot of unused F-13 that would still be clean and in your spray bottle for future use if you had used the spray bottle onto brush (on extension pole) method.

Now your bottle of F-13 will last even longer.

Still though, your brush will get dirty even with the spray onto brush method so what I do is periodically rinse it with water from the jet nozzle & garden hose, which is already right there at my side anyway. Just shake the excess water from the brush and maybe dry it as much as you can with a dry rag so it won’t dilute your spray bottle mix

Dirty black streaked gutters are time consuming. If it goes too fast we may be using too strong of a mix and doing damage to the finish on the gutters. I start with a weaker mix (bump it up a little for really dirty gutters) and take as much time as needed in order to hopefully avoid doing damage and losing my rear.

F-13 is the BOMB!


In a couple of my posts in this thread I stated that F-13 is a butyl based cleaner. I was wrong about that! F-13 is not a butyl based chemical. The advertisements for F-13 claim that butyl based cleaners attack the paint but that F-13 is not butyl based and only attacks the oxidation, not the paint.

I don’t know about F-13 only attacking the oxidation and not the paint but it does get black streaks off of gutters. I’m sure that F-13 would damage the paint if it was mixed too strong so I will continue to take all of the precautions that I spoke of in this thread.

I have now gone back through this thread and edited my posts that stated that F-13 is a butyl based cleaner. (Once again for the record…F-13 is not a butyl based cleaner). I also edited out some of my wording that seemed to offend one of the previous posters in this thread. I didn’t mean to offend anyone, but looking back at my wording I could understand how someone would have been a bit miffed.

Right, F-13 is a completely different animal than the butyl-based gutter cleaners. It ONLY removes oxidation, not paint.

Good stuff.
Buy from Bob, so he can buy me more drinks.

In the uk I use a vikan mono brush and either a garden sprayer to apply trf (traffic film remover) you may call it trusk wash, but your local car wash will have it.

I do not know what F13 is.

if I can reach the gutters with the garden sprayer (pump action) I dip in the brush and wfp if down.

Not ever had a problem doing it this way.


where do you purchase the F 13. Thanks

Perfect Pane
Los Alamitos