Leland,

The run off from cedar appears to eat pin holes and bigger in copper
gutters.  I was frustrated for a long time by my inability to find an
authoritative text source.  All I had to go on was the word of the elders
of our profession...but when Jim Askins is one of them elders, its good
enough for me.

Meanwhile I ran into a fun little contemptory detail.  Cedar used on the
sloped underside of a canapy thing.  Copper clad columns holding the canopy
up.  The copper adjacent to the dedar ceiling, catching the run off, is
shiny and new looking.  Lower it has a nice developing patina.  Seems to me
that if I wanted to keep copper shiny I'd have to scrub it with something
mildly abrasive every few days.  I suggest that the cedar run off is doing
the same thing.

I would not use copper in flashings, valley flashings or gutters on a cedar
roof.  I do use it for ridge flashing.  In that condition it appears to
prevent the growth of mold on the shingles.  I believe I stole that one
from someone in NPS also...probably Askins...or one who was influenced by
him.

I'd like to read Baerman's article, can you tell me where to find it?

Don't be surprised when Revere, RCSSB or other suppliers and manufacturers
don't seem to know anything about incompatibilities.  Read the fine print.
Also, note what they are guaranteeing for performance.  Lots of wood
shingle roofs are not leaking that are covered...or partially covered with
completely rotted shingles.  That's what happens when you make the shingle
a reduntant system.  Building materials need to do work.  Kind of like us.

-jc

Leland Torrence wrote:

> Hello,
> I work occasionally with Donald Baerman, AIA, who I believe was the
> first person to write an article on the copper/cedar thing.  I convinced
> him to finally go back to copper (it looks good with wood).  I have used
> and seen copper with cedar all my life and have not see problems  in
> deference to what I have read.  I called a technical person at Obdyke
> and Revere a few years back but can't remember what their response was!
> You should call and let us know.
>         Yale insists on continuing the use of lead coated copper, which
> is an environmental hazard as well as a worker issue (which is not
> covered by OSHA or EPA).  Someone should do a study on lead content of
> water run off and blood levels of roofers who handle the stuff all day.
> As well, within a few years the lead has worn off  at drip points (gee,
> where did it go, Dave?) and the copper shows through.  I suggest using
> copper and increasing the gauge at valleys.
>         Don't get me wrong, I love lead.  It is great to work and can be
> very pretty.  It is truly the best thing ever added to paint,  But if it
> is truly a hazard we should not continue using it.
> Best,
> Leland
>
> -----Original Message-----
> From: The weather listserv for hotheads....
> [mailto:[log in to unmask]] On Behalf Of Heidi
> Harendza
> Sent: Tuesday, August 27, 2002 8:49 PM
> To: [log in to unmask]
> Subject: Re: Roofing question
>
> In a message dated 08/27/2002 5:09:01 PM Eastern Daylight Time,
> [log in to unmask] writes:
>
> >  We also used some sort of drainage mat (Cedarbreather, by Benj
> > Opdyke, I
> > think) beneath the roof shingles, so the shingles got to "breathe" and
> their
> > undersides didn't stay wet against tar paper.
>
> Well... as far as I know... we won't be using any tar paper. There isn't
> a subroof or anything... just rafters and shingles and shingle lath. I
> did read about the copper -cedar issue, so one of the roofing
> contractors that has been helping me set up our specifications
> recommended lead-coated copper.
>
> Any other caveats that you can think of? Tell me now so I don't look
> like a
> goob-- I'll throw myself off a bridge if I screw this one up after being
> called in as the "expert."
>
> -Heidi
>
> --
> To terminate puerile preservation prattling among pals and the
> uncoffee-ed, or to change your settings, go to:
> <http://maelstrom.stjohns.edu/archives/bullamanka-pinheads.html>
>
> --
> To terminate puerile preservation prattling among pals and the
> uncoffee-ed, or to change your settings, go to:
> <http://maelstrom.stjohns.edu/archives/bullamanka-pinheads.html>