Black streaks?

[JeffW 14]

I have been washing houses for ten years now,.....yet I am still uncertain what causes the perfectly spaced black streaks on rain gutters.Could someone enlighten me.I have seen this on gutters that are only a year old or less.I can clean them easily(as long as it's warm enough),... but would still like to know what causes them.Thanks for any and all positive responses.

[Beth n Rod 1,279]

As rain rushes from the roof, it carries with it soluble materials from the roofs ashpalt and bonds electrostatically to the painted surfaces on the gutters. They can be removed, but repeated removal also compromises the anodized paint on the gutters and could eventually end up with bare spots as paint comes off with each cleaning in most cases.

In short, the process is called electrostatic bonding of the ashpalt material to the gutters painted surfaces.

Butyl based cleaners can remove these streaks as well as a diluted sodium hydroxide based cleaner. But remember, it will eventually take off the paint. We recommend to our customers to only have this service done when they are about to sell the property to add curb appeal.

They ultimately have the final say of course, but educate them to the down sides as well.

Rod~

[RyanH 14]

I've been thinking about a coating to put on the gutters after they are cleaned. The gutters were just put on my house about 5 months ago and already have pretty bad streaks and I intend to keep them clean but, like Rod said, I don't want my paint to be gone in the next two years after cleaning. I wonder if regular application of WD-40 will work for this too? It does everything else......

[JeffW 14]

Good answers,...thank you very much!! I always like to know more than the customer.

[PLD 14]

As rain rushes from the roof, it carries with it soluble materials from the roofs ashpalt and bonds electrostatically to the painted surfaces on the gutters. They can be removed, but repeated removal also compromises the anodized paint on the gutters and could eventually end up with bare spots as paint comes off with each cleaning in most cases.In short, the process is called electrostatic bonding of the ashpalt material to the gutters painted surfaces.

Rod,

I had the exact same school of thought until I inherited a 5x8 trailer was for the band this year. Now I'm not so sure. The trailer is 100% white baked aluminum and all caulking is white. Just like a gutter. It stays with under a brick overhang (sometimes) or on a wide open parking lot(mostly). It streaks identically, and the streaks respond just like gutter streaks. And by respond I mean butyl works, soap/bleach do not, applied dry works better than pre-wetting)

With no asphault in sight (other than the parking lot itself), and less than 10 miles between cleanings, it has no significant contact with tar and/or road grime. Take now for example, it has not moved all summer and it's streaked since our last cleaning in July. Nothing on the front (dirt, exhaust), no horizontal stripes (road grime, etc), just thin black stripes that expand over time into larger grey/black discoloration.

It's certainly anecdotal, but here's why i think there is more to this puzzle than we currently believe it to be.

For starters, examine the aluminum facia covers on the non-gutter side of (mostly vinyl) houses. They too are anodized aluminum and experience roof runoff (albiet to a much smaller degree) but exhibit almost NO "tar streaks". In fact, the aluminum trim/flashing is usually formed from the same roll of material as the gutters are. But even under gutters that are badly streaked, the blackened fasica almost never needs degreasing. By and large, the only black that ever appears on fascia flashing comes off with bleach. Also, flashing that that is in close contact with the roof almost never shows evidence of tar splashing as would be expected if it was in significant levels in the surface water.

I tend to believe that surface temps are a major contributing factor because the trailer and gutter stay relatively hot while the flashing has a stud behind it to act as a heat sink.

Anyway, rainwater containing oils from the roof should not be reaching the gutter surface in any great quantity in a properly installed and maintained gutter. In a normal situation, far more fresh rainwater would reach the face than contaminated water. Yet I've seen many clean free-flowing gutters that were heavily streaked, and clogged gutters that were clean. Also, the degree of splash-over should vary with roof pitch. Yet based on the degree of streaking, the levels of gutter tarring are not closely tied to either roof pitch.

All that said... It certainly responds well to degreaser/hydroxide/metasilicate which indicates it is an oil of sorts. Yet it fails to respond to bleach is a decent mild degreaser and will draw a great deal of tar out of asphault. All in all, I think there is more at work behind gutter streaking than simple electrostatic bonding of oils.

Anybody wanna work on a project to collect some data?

[PLD 14]

One more thing. I just walked around my own house and looked at the gutters that are in need of de-streaking. I looked UNDER the downspout bends. A good bit deal of oil laden water drips under the elbow before landing in the splash block. Outside of some algae, Nothing. Yet this area should be the blackest section of them all.

[CCPC 26]

Observations can go a really long way. I have the answer to the streaked gutter dilima.

I always wondered how gutters can get so streaked with atleast four inches between the roof line and the outside of the gutter. Well, it turns out these streaks are not from overflowing water out of the gutter, they actually are from rain water bouncing off of the roof, near the gutter and the drops land on the top ledge of the gutter and begin to run down (hence why most are streaked vs a cloud of black, which you will see in areas were there is overflow).

How do I know this for fact?

Because I watched it happen from my own eyes. I was on a job about a month ago, and it started raining as it rained I happened to be in just the right spot where I could see the drops bouncing off of the roof and landing on the top of the gutters edge, and then begin to slowly run down the outerside of the gutter. I actually meant to share this bit of information after that, but forgot.

As far as the trailer is concerned, the only explantion I can think off is the same as the gutters. The rain bounces off the ashpalt pavment lands a top the trailer edge and runs down.

[RyanH 14]

I used to think it was oils from the shingles as well. I usually don't see the problem on ranch-style houses where the roofs are not very steep. Common building practice has become to have very steep roofs and very small gutters (typically no larger than 4 inches wide). With the steep roofs, small gutters, and even smaller and fewer downspouts (common now to have on on either side of a house up to a 100' span), it doesn't take a heavy rain for the gutters to fill up and flow over the egde (I've seen this on many many many houses around here).

BUT, phillip brings up an interesting point: I've also seen these on my parents' motorhome and a friends enclosed trailer. Motorhome is parked on grass, trailer is parked on asphalt. And every white enclosed trailer for sale at home depot around here has them (very bad). I'm beginning to wonder if he may be onto something. Perhaps it is aluminum oxide bleeding from a fastener, or something from the anodizing process. I'll look deeper into this and do a few tests around the house. We've found an answer for the myococaphelia or whatever the hell that algae on the roof is called, we should be able to give a qualified answer for the gutters as well!

[Dave O 15]

You mean like this one? Just like one big gutter. Look at that shine LOL. :lglolly:

[seymore 90]

You mean like this one? Just like one big gutter. Look at that shine LOL. :lglolly:

Dangggg nice job Dave :cool:

Did that chem you use take any paint off?

[PLD 14]

Well, it turns out these streaks are not from overflowing water out of the gutter, they actually are from rain water bouncing off of the roof, near the gutter and the drops land on the top ledge of the gutter and begin to run down

I an see the water flow, but not the link to tar. If that is indeed the cause, then why is close proximity fascia not affected?

As far as the trailer is concerned, the only explantion I can think off is the same as the gutters. The rain bounces off the ashpalt pavment lands a top the trailer edge and runs down.

That's one hell of a bounce. At least 7ft vertically.

[PLD 14]

Perhaps it is aluminum oxide bleeding from a fastener, or something from the anodizing process.

Wondered that myself, but there's one problem. The fascia covers are made from the same coil of aluminum. Roll through a machine for guttters, cut and break for fascia. And they don't exhibit the same problem.

If we can find the root cause, we can perhaps make a more sensible approach to tackling it. Oils may be the cause as we have always suspected and told others. But why are some parts of the house affected while others just inches away remain unsoiled?

[Cleveland Mobile 14]

Trailers get the black streaks from the sealer that is used on the pieces that are where the roof and the side meet. Its also a similar material to shingles.

Andy

[JimCrossley 14]

We clean condos that have white anodized aluminum roofs over their front porchs and the roofs feed into white gutters. The gutters get streaks along with the metal roofs. There is not any tar in proximity to the gutter.

I think the black marks come as a result of the carbon particles in the atmosphere that is brought to ground level thru the rain.

[PLD 14]

Trailers get the black streaks from the sealer that is used on the pieces that are where the roof and the side meet. Its also a similar material to shingles.

Andy

Even if the material is white? This trailer is sealed with what looks like household caulk. I'm sure it's something else, but it isn't black or grey.

[Beth n Rod 1,279]

Well, heres one more for the mix...Aluminum oxidizes as well. Aluminum is the common denominator in all the posts in this thread so I would venture to suggest that it is oxidation that has formed a bond to these surfaces. Electrostatic bonding is still the primary contributor to the stains forming on these surfaces.

I havent got any photos of this one, but I have done some house washes where the windows have dark grey streaks similar to the ones on gutters running down from the left and right sides of the windows that have the new aluminum capping installed. It was a Beotch to get off and still left some residue behind that would not come out completely.

Anyone else?

Rod~

[RyanH 14]

How's this for a stretch.....

when to dissimilar metals contact each other, they generate an electric current. The magnitude of the voltage is related to the temperature (hotter temperatures = higher voltage). Could it be related (and I'm really stretching here) to the fact that gutters typically are made of aluminum and the nails are tyipcally galvanized, and the current in the metal is electrically attracting particles from the air? Kind of like those machines that use electric plates to clean air (Ionic Breeze is one type I think, Oreck makes another)? Trailers use rivets and sheet metal or aluminum....are these metals different (I wouldn't think rivets are aluminum just because the tensile strength isn't that great).

Now, for the SUUUUUPPPPEEERRRR stretch.....

I'm not much into how electricity flows, but doesn't it have a wave pattern associated with it? With highs and lows? Could this periodicity or frequency be related to the spacing in the black streaks? Or could the metal possibly have nonuniform thickness along the length causing a difference in the current (more or less resistance at thicker or thinner spots) affecting the amount of particles captured?

Whew! hows that for a bowl of BS cereal for breakfast?!

[jason c. 14]

as jeff originaly posted and i'm sure we can all attest, the streaks are pretty evenly space out along the gutters. pattern like. i think the same goes for the trailer as well. maybey they are crimped by a machine at the factory every inch or so and that may cause it to stay on the gutters perm. after they are painted over...thus bleeding through the paint every now and then?

i love b.s. in the morning!!!

[5282jt 14]

First off, I have been in business since 1978, so this is nothing new to me.

I know this can't be from asphalt roofs, because I see it just as often on mobile home gutter faces, with vinyl or aluminum pan roofs, and gutter faces on tile roofs. { Here in S.W. Florida } In fact, last week I cleaned a white cement tile roof and & House, the gutter faces were black and green with mildew. { This house appeared to never have been cleaned before and it was about 20 years old } After I cleaned it, the roof was nice and white and so were the gutters - EXCEPT for the common black streaks. The people were thrilled. AT THE MOMENT. Then called me back the next day about the black streaks. I told them that those streaks were very common and pressure cleaning did not remove them. He said "They weren't there before you worked here, it must have been something that you sprayed on them!" { These people were about 70 years old and the guy got more and more angry with every word he spoke! } I told him, "You didn't see them before, because your gutters were black with thick mildew. The streaking was hidden."

Then he started screaming at me "DON'T TELL ME THEY WERE ALREADY THERE! YOU ARE A LIAR"

I said "Well, i'm not going to stay on the phone with you screaming at me, goodbye."

My theory, is that these streaks are caused by airborn polution from car exaust etc. I see no other explanation.

[JeffW 14]

Well, whatever it is I am very thankful for all the replies so far.I did'nt realize it was such a hot debate.I thought it was going to be a simple answer,... and I actually felt like a greenhorn even asking this question,.....I don't feel quite so alone on this now.Thanks to all!!

[Beth n Rod 1,279]

http://www.xterior.com/html/_chemicals_1.html

[CCPC 26]

I an see the water flow, but not the link to tar. If that is indeed the cause, then why is close proximity fascia not affected?

I see black streaks on facia and flashing all the time. Actually, on most homes I wash, the fascia/flashing is worse than the gutters.

That's one hell of a bounce. At least 7ft vertically.

Thought you were talking about an open trailer, my bad.

[CCPC 26]

I'm not postive of what causes the black in the streaks, but I allready explained why you see perfect little line streaks on gutters. When you see streaks on the gutters, its not from overflow, its from drips running down the side. When you see a black cloudy area, that's where its overflowing.

[RyanH 14]

I was at a friends house today and looked at his gutters. The roof is entirely tin (oooolllldddd roof) or aluminum (whatever they used many years ago). The gutters are more than large enough to handle the hardest of downpoors without overflow. There is no tar/asphalt within 500 yards of these things (large pasture). I'm thinking I may look into my electric current theory. Has anyone noticed streaks on vinyl gutters? I've never noticed them on non-metallic surfaces surrounding gutters (fascia, siding, etc.)

[CCPC 26]

I was at a friends house today and looked at his gutters. The roof is entirely tin (oooolllldddd roof) or aluminum (whatever they used many years ago). The gutters are more than large enough to handle the hardest of downpoors without overflow. There is no tar/asphalt within 500 yards of these things (large pasture). I'm thinking I may look into my electric current theory. Has anyone noticed streaks on vinyl gutters? I've never noticed them on non-metallic surfaces surrounding gutters (fascia, siding, etc.)

Come to think of it, where valleys on the roof run off onto the facia, I do see the vinyle soffits just underneath with some black on it as well, but always underneath alum. facia.

[JeffW 14]

Ryan, now that you bring up the vinyl gutter thing, I do remember seeing this problem on plastic or vinyl gutters.One more hurdle to jump I guess.And in my experience the plastic gutters are harder to clean than aluminum.But then again I don't run into the plastic ones very often.