[TheForge] Update [OT - Asphalt shingle rot? (Lichen)]

[Peter Fels & Phoebe Palmer]

Place the pennies with a dab of roofing tar.

Bruce Freeman wrote:
> Well, this is amusing so I thought you might like an update.
> 
> Before dropping $60+ on copper flashing, I did some more Web-research.
>  Turns out that those of you who spoke up are apparently right --
> copper OR zinc cations will kill lichens.
> 
> So, what's the cheapest source of copper AND zinc metals?  You guessed
> it -- "copper" pennies.  So now, if you look real close, you'll see
> pennies scattered on the north-facing side of my roof, mostly near the
> peak.  I had only about $5 worth of pennies around when I did this, so
> might go buy another $10 worth for the effort.  I figure with rain and
> winds, these will tend to wash down the roof, but I'll cross that
> bridge when I come to it.
> 
> Meanwhile, I haven't given up on the notion of spraying the roof with
> copper sulfate, but I've been trying to figure how and how much.
> Seems to me that if a strip of copper foil across the roof will
> protect the roof for 30 years or more (so claims that manufacturer),
> then the concentration of copper needed could NOT be very high.  I
> haven't actually worked out a number, but it must be vanishingly
> small.
> 
> So I envision doing something like putting a half-teaspoon (if that
> much) copper sulfate, dissolved in water, in a sprayer and spraying
> the roof with it.  The problem with this is that I do NOT want to
> inhale the stuff.  So I could use goggles and mask and wait till the
> wind is right, or I could come up with an alternative way.  I could
> possibly roll it on like paint, and if I did that I wouldn't even need
> to cover the whole roof, as it will wash down from the peak to the
> rest of the roof.
> 
> Still thinking on it.
>