zink strips - Contractor Talk - Professional Construction and Remodeling Forum

bmaurice · 10-13-2009, 03:52 PM

anyone use zinc strips you put just before the ridge. HO wanted them installed on his new roof. i think they are dumb and i dont see them working on a roof. i know boats use the **** to keep the barnicals or something off, but its two totally differnt applications.

**genecarp** · 10-13-2009, 04:21 PM

For what

Tinstaafl · 10-13-2009, 04:44 PM

They're used to prevent moss and algae growth. Not perfect, but they work a heckuva lot better than nothing at all.

**genecarp** · 10-13-2009, 04:46 PM

Quote:

Originally Posted by Tinstaafl

They're used to prevent moss and algae growth. Not perfect, but they work a heckuva lot better than nothing at all.

You ever use them in PA?, never seen them, never used them here, 30 years

.

Tinstaafl · 10-13-2009, 05:09 PM

I haven't used them personally, though I keep intending to. I have a north-facing section of roof on my own house that loves to grow stuff.

I've seen them on roofs that looked pretty decent--though I can't honestly say what those roofs would have looked like without 'em. If you check around and do your homework, the theory is sound. Copper works too.

WarnerConstInc. · 10-13-2009, 05:50 PM

I thought it was Zinc.

They work, for about 7-10 years.

**framerman** · 10-13-2009, 06:13 PM

I've seen it on about 1 in 100 homes here. Not sure of the results.

PA woodbutcher · 10-13-2009, 06:33 PM

I put some on a garage that was tucked back in the woods last year. Customer had moss and chit growing on all her roof.....will be doing the house in the next couple of years.

Strips didn't go down bad and are in like 4' lengths. Not real visable from the ground on a 5/12

theflynner · 10-13-2009, 10:29 PM

The logic is that zinc strips are made of a heavy metal. The metal leeches ions which are acidic enough to be toxic to algae. Copper, magnisum and nickel can also be used.

If you look at a typical roof with dark streaks, you will see that the downslope area of flues and flashing are clean.

3M sells shingle granuals to most of the major shingle manufactures. For an addiltional price, they mix small copper particals with the granuals to help retard algea.

John in MN

dougger222 · 10-14-2009, 09:14 AM

I have put them on several roofs but not many since Certainteed has put copper granuals from 3M into the shingles. A source tells me the Landmark has the most copper content of any shingle on the market today, 10%. By way of comparison the competition uses 3-7% copper granuals.

The last roof we did it on was an AR application but the roof was in the woods. We put it on both sides of the ridge, it was a gable four sided house perfect for zinc strips. Hip roofs on the other hand pose a problem with installing zinc strips.

Most commonly the zinc strips are installed right below the ridge caps on the North sides of roofs. Have bought them as either pre bent ribbed 4 foot sections and in 50ft rolls. The rolled stuff goes on fast but you must use additional nails to secure.

Two stories about zinc strips.

#1. A home owner had me replace his roof and wanted the zinc strips detached and reset which we did. In talking he said that his green roof was stained really bad a couple years ago so he had it profesionaly cleaned with the three part system. In less than 6 months the North slope again was totaly stained up. Finding out about the zinc strips he decided to have them installed just below the ridge. To his amazement all the staining went away by just installing the strips. No additional roof cleaning was ever performed.

#2. An estimator friend of mine was called to a lightening job a few years ago. His findings was that the lightening hit the zinc strip and traveled along the zinc from one end to the other popping all the nails out of the ridge as it went along.

Most shingle manufacturers warrant the shingles to be free from algea staining with the AR version to 10 years. In some areas and with some shingles that warranty is as high as 15 years.

Like others have mentioned on really old roofs you can see clean shingles below the chimney and metal vents while the rest of the roof is an eye sore. That being said I feel the zinc strips should prohibit the staining for many, many years perhaps as long as they are on the roof.

Other than the lightening situation I see no other issues with installing zinc strips on roofs. What I've found and with talking to adjusters and roofing engineers is they seem to think the streaking is air born and can travel from roof to roof. I feel this is partialy true but some trees make it happen while others don't. In some neighborhoods with roofs 8-12+ years old every one has streaking while across town roofs the same age will have no streaking.

JTW · 10-14-2009, 09:25 AM

Interesting post. It seems they are starting to become popular here. Staining is a big problem, I am guessing the salty ocean air is not helping. It makes me cringe when I see these roofs all streaked up! And yes, I beleive Certainteed does use the highest copper granule content. Th tree theory is interesting, I had not thought of that as it sems around here, one could be in the middle of a 10 acre field and still be full of streaks.

apkole · 10-15-2009, 06:38 PM

I've installed zinc strips on several roofs, going back at least 10 - 12 years. My experience has been that they are very effective for about the first 5-8 feet of roof immediately below the installed strips. Any farther away than that and the dilution of the metal limits the inhibition of moss and algae growth.

Installed them for a customer about 12 years ago who had first seen them in his travels south to florida. I drove by the house a few weeks ago and I'm not impressed.

We installed zinc strips on A-framed camp buildings - 12 pitch roofs with a 12' eve to peak. The site is heavily wooded and shaded. The top 1/2 of the roof area is relatively free of moss and algae. Farther down it's as if there was no treatment at all.

I've spoken with our distributor, and they concur with what I've been observing. A second application at the halfway elevation of the slope is the best suggestion they've come up with. Or . . . . re -shingle with a good AR rated shingle . . . but then that's only guaranteed for 10 - 15 years.

Take your pick . . .

dougger222 · 10-22-2009, 07:22 AM

Quote:

Originally Posted by apkole

I've installed zinc strips on several roofs, going back at least 10 - 12 years. My experience has been that they are very effective for about the first 5-8 feet of roof immediately below the installed strips. Any farther away than that and the dilution of the metal limits the inhibition of moss and algae growth.

Installed them for a customer about 12 years ago who had first seen them in his travels south to florida. I drove by the house a few weeks ago and I'm not impressed.

We installed zinc strips on A-framed camp buildings - 12 pitch roofs with a 12' eve to peak. The site is heavily wooded and shaded. The top 1/2 of the roof area is relatively free of moss and algae. Farther down it's as if there was no treatment at all.

I've spoken with our distributor, and they concur with what I've been observing. A second application at the halfway elevation of the slope is the best suggestion they've come up with. Or . . . . re -shingle with a good AR rated shingle . . . but then that's only guaranteed for 10 - 15 years.

Take your pick . . .

You are absolutely right. The other day I noticed the roofs across the street all had streaking on the North slopes. It didn't matter the color of shingles they all had streaks. One of the roofs which I did an addition on 5 years ago had zinc strips on the original part of the roof which is now 10 years old. The top of the roof was clean for about 7-8ft then the rest was stained. Due to the long rakes this roof would need 3-4 sets to make it totaly clean.

The part I did the addition on was totally clean with zinc strips but it's only 5 years old.