I just saw Ask the Old House episode with Tommy Silva insstalling zinc strips to help remove algae and fungus off the shingles. Would copper strips(flashing) installed on the roof ridge provide the same anti-moss/fungus growth on the roof shingles?
Thanks in advance,
Fred
Replies
Would copper strips(flashing) installed on the roof ridge provide the same anti-moss/fungus growth on the roof shingles?
As long as water runs across the strips before proceeding down the roof, yes.
Birth, school, work, death.....................
http://grantlogan.net/
How much exposure?
I called around here and found a supplier for the zinc strips. Guy on the phone told me they get nailed under the shingles, that the dampness and oxygen still find the strips and "shed" the killing again (zinc oxide?) on down the roof.
what makes you an expert on copper.huhhh?The secret of Zen in two words is, "Not always so"!
When we meet, we say, Namaste'..it means..
I honor the place in you where the entire universe resides,
I honor the place in you of love, of light, of truth, of peace.
I honor the place within you where if you are in that place in you
and I am in that place in me, there is only one of us.
Yes, but either solution can result in streakiness, depending on factors which escape my knowledge.
That is, I often see roofs with copper flashings (usually older churches or residences) where the anti-gunk effects are noticable because they don't do the job completely and there are streaks.
(Saw a streaky one the other day and was going to take a pic but was running late and now I don't remember where I saw it!)
What I don;t know, of course, is how are out there I don't notice because they are working as intended.
I've posted a couple of pics here of some streaky roofs; maybe search for zinc copper and moss
I can tell you for sure that they don't work in south Florida. We installed about 5 or 600 feet of zinc on a shopping center roof several years ago. They may as well have been made of plastic. I saw the TOH epsiode you're talking about and would just about guarantee that zinc strips won't do a thing about all the lichen on that roof.
Not sure if it has much bearing in real world situations but copper is higher on the the galvanic scale than either steel or zinc. A roof nailed with galvanized roofing nails that contact the copper could loose their galvanization to the copper and the steel could deteriorate.
I'm not sure how the copper ions in the water that contacts the copper might react in time but it seems reasonable that they might corrode both the zinc galvanizing on nails and flashing and, given enough time, the steel underneath.
It seems reasonable that zinc strip would not have a similar effect.
Both metals oxidize...that is they lose their effectiveness. Around here we just go onto the roof once in a wipswhile and liberally sprinkle "Sunlight" laundry detergent, which kills moss, etc. Brush off when blackened and dead.
All the best...
To those who know - this may be obvious. To those who don't - I hope I've helped.
The copper may work better than the zinc. It's the most active ingredient in the old CCA treated wood. The copper kept the mould/rot at bay; the arsenic as for the insects.