Zinc Strip in Roof?

[spschroeder]

Building my garage in a wooded area. Black asphalt shingles.

I heard about 'zinc strips' that install up under your ridge cap, the length of the building, to prevent moss from growing on the roof.

http://www.menards.com/main/building-materials/roofing-soffits-gutters/roofing/roof-edge-tools-accessories/moss-zinc-strip-50-roll/p-1380342-c-5817.htm

Anybody use them? What do you think? Do they work?

Does anyone have pictures of their roof with these installed?? I'm interested in if they are visible from the ground and what they look like on a black roof...product says they are supposed to be exposed ~2 inches.

Thanks,
-Steve

 

[91FE]

Considered the same on a shady porch roof, but decided to sell the house instead

 

[b-body-bob]

I asked the roofer who worked on my reno about it and he said it'd cost me less to trim the trees like I should anyway. Anyway, he said it was a hard to install if the wind kicks up because it's soft thin and light.

 

[McFarmer]

Used to be galvanized ridge caps, shingles lasted longer with them.

 

[Stuart in MN]

Copper or zinc strips will work. From the This Old House website:

To keep the algae from coming back, insert 6-inch-wide strips of zinc or copper under the row of shingling closest to the roof peak, leaving an inch or two of the lower edge exposed to the weather. That way whenever it rains, some of the metal molecules will wash down the roof and kill any algae trying to regain a foothold on your shingles.

 

[JakeKohl]

The zinc in the galvanized vents on my roof did a number on the mildew under them. I would say the zinc strips will do really well. However, a lot of the new roofing has anti-growth additives (copper/zinc?) and guarantee against black streaks for some period. My new roof on my garage guaranteed something like 10 years against streaking.

Oooppps forgot the pic

20140708_195417-1
by Green Room Graphics, on Flickr

 

[rlitman]

I don't have issues with streaking, but buildup from an oak tree let clumps of moss grow on my garage roof.

I used a 5 gallon tank sprayer with a stream nozzle that could reach my roof. I put in half a dozen scoops of oxy-clean, with plain water, and sprayed the roof until it was just starting to foam white. Within a week, the moss was yellowing and browning. Within a few months it was gone.

Be careful removing moss. If you're too aggressive, you can lose granules, and that ruins shingles.

 

[tomd]

I installed them on a roof 6 years ago. Previously had moss, now it's clean.
They worked for me.

 

[owenst7]

My family always installed them in Alaska (roofing contractors). Works great against lichen also.

Whatever roofer said it was expensive is an idiot. I'm pretty sure they sell rolls of it at Home Depot, and it takes all of about two seconds to install. We also never had any wind issues despite annual 100+ mph winds.

It doesn't take much reveal to be effective. Depending on the pitch and your yard, you can usually camoflauge it to where it isn't noticeable.

 

[Kevin54]

I've always heard that if you run a copper wire on each side along the edge of the ridge cap, that it will stop the roof from becoming discolored. The rain hitting the copper wire and running down the roof, helps to stop whatever causes the discoloration. I've never heard that about a zinc strip stopping algae though.

I did do a search in BING for this:

copper wire or zinc strips stops discoloration and moss on roof

It basically states that it will prevent moss or algae from starting, but will not take care of existing moss or algae or discoloration, and will need to be cleaned first.



`

 

[sr71]

Jake is correct …most of the mid range and up singles contain copper to help prevent the growth of algae (black streaks you see). When I did my roof I had copper strips added for an extra bit of insurance. Considering the cost of a roof job, paying to add the copper or zinc strips is no brainer.

They are visible from the ground in the first year …..but as they change color become less and less visible. I like the look …almost like a bit of cabinet trim - makes the job somehow look more professional.

 

[cdestuck]

I put them on my garage roof and it never helped a bit. Was a waste of time and money for me

 

[spschroeder]

Good input, everyone. Thanks!

 

[MScott]

Before I replaced the roof on my lake side cottage, there was a lot of moss growing on the shingles. The chimney, however, had a galvanized flashing around it and below that was a triangular shaped area with absolutely no moss. The zinc bearing runoff from the flashing was obviously keeping that area free of buildup. I would certainly have used the zinc strip when re roofing if I hadn't switched to a metal roof and gotten rid of the problem completely.

 

[Backlight]

I have a zinc strip on my cottage, no moss. On the cabin/shed, no strip, lots of moss. Both are equally shaded, same pitch and have the same trees nearby. Based on this I'd say they work and would install again.

 

[Mxrcr]

The do work. I layed shingles for 10 years. Like stated many of the nicer shingles have copper or other additives to help. That said, zinc strips will last longer, and if installed correctly should not create an issue with any wind. I would say go for it, it is cheap insurance.:rocker

 

[Dustball]

Here's a 4-year review by a local inspector- http://www.structuretech1.com/2014/07/zinc-strips-mossy-roof-four-years-later/

 

[mds5951]

Just watched this episode the other night when i couldnt sleep....might be helpful!

This old house: Mossy Roof, Valve Repair, Shade Ground Cover | Episode 7, Season 4 (2006)

 

[rslaback]

Whenever anyone asks me if adding a zinc strip to a roof really helps or not I always tell them about this barn that used to be on my drive home. By the way, as you can see, it has nothing to do with trees etc. as there is clearly nothing shading the barn other than itself. The issue is all about sunlight and how quickly it dries when wet.

 

[McFarmer]

Whenever anyone asks me if adding a zinc strip to a roof really helps or not I always tell them about this barn that used to be on my drive home. By the way, as you can see, it has nothing to do with trees etc. as there is clearly nothing shading the barn other than itself. The issue is all about sunlight and how quickly it dries when wet.

No, I think the zinc is killing the organisms that weather the shingles.

Or did I misunderstand ?

 

[rslaback]

No, I think the zinc is killing the organisms that weather the shingles.

Or did I misunderstand ?

You are correct that the zinc kills the organism. But that organism needs warm and wet which is why the south side of the roof never has growth.