[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: Roof Cleaning



Moved to another house last summer.  It needed a new roof and I wanted to
use as light a color as possible to reduce cooling load.  However, here
in the land where Tilex was invented, your white roof is soon black from 
fungal growth and the cooling load goes back up.  I bought
shingles on which some of the grit is mixed with copper salts.  These
slowly leach out and prevent fungal and algae growth.  This spring I spoke
with Kelly Moran of the Palo Alto POTW P2 program.  They are having
problems with zinc and copper and cannot find all the sources.  I
suggested they look into this type of roof shingle to quantify how much
of a contibution to copper load they might be causing. No results yet. 

I estimated that the roof loses about 30 milligrams per year of copper.  I
had to balance that against the increased energy consumption of a fungused
roof or a dark roof that would not show fungus.  Also had to consider the
energy it takes to get bleach onto the roof, protect the plants, collect
the runoff and what happens when you dump the stuff down the sewer.
Sounds like an EPA life cycle assessment contracted to Franklin.  The
crucial decision point was my wife saying "you can have as light a roof as
you want as long as it doesn't look funky after two years".  Don't even
ask about the pool. 

Bill Bilkovich, EQC
3651 Cherry Bluff Ln
Tallahassee, Fl 32312-1001
Fax 904-906-9816 Voice 904-894-2780
bilko@vistech.net


On Tue, 5 Aug 1997, David Williams wrote:

> Thanks Steve for the reminder.  I've also read that a strip of copper 
> will serve the same purpose as a strip of zinc. - David
> 
> 
> > From:          "Hillenbrand, Steve J." <sjhillenbrand@tva.gov>
> > To:            "'p2tech@great-lakes.net'" <p2tech@great-lakes.net>
> > Cc:            "McEntyre, Charles L." <clmcentyre@tva.gov>,
> >                "Phillips, Joseph W."
> >                <jwphillips@tva.gov>,
> >                "Mantooth, Jim G." <jgmantooth@tva.gov>,
> >                "Loney, Jon M." <jmloney@tva.gov>, "Brown, Lynn R." <lrbrown@tva.gov>,
> >                "Scheffler, Peter K." <pkscheffler@tva.gov>
> > Cc:            "Williams, Ronald J." <rjwilliams@tva.gov>
> > Subject:       RE: Roof Cleaning
> > Date:          Tue, 5 Aug 1997 09:59:14 -0400
> > Reply-to:      p2tech@great-lakes.net
> 
> > I heard of something that I tried that is supposed to prevent moss and
> > fungus.  I applied a thin strip of zinc paint (available at farmer's
> > co-op but is fairly expensive by the gallon) along peak of roof (I
> > applied to lower part of ridge vent where it would not show but is
> > exposed to run off from top of ridge vent).  I have heard that tacking a
> > strip of galvanized metal along peak of roof also works.
> > 
> > The theory is that the minute amount of zinc that washes off the paint
> > or strip is enough to discourage growth of moss or fungus.  I have only
> > used this on my house for a couple of years since I had the moss and
> > fungus removed (at fair expense) so I do not know if it is working yet
> > (I can see no obvious growth yet).
> > 
> > This is only anecdotal but is a source reduction option if it works.
> > 
> > >----------
> > >From: 	David Williams[SMTP:David_Williams@owr.ehnr.state.nc.us]
> > >Sent: 	Tuesday, August 05, 1997 10:02 AM
> > >To: 	p2tech@great-lakes.net
> > >Subject: 	Re:  Roof Cleaning
> > >
> > >I asked a similar question earlier this year of the Cooperative 
> > >Extension Service in NC, and I was given a couple of options:
> > >
> > >1) Chlorine bleach & water 1 cup bleach/gallon of water.  Apply the 
> > >solution, let soak a few minutes, brush lightly (careful not to strip 
> > >the grit off) and rinse.
> > >
> > >2) Trisodium phosphate 4-6 Tbsp/gal H20.  Use the same application 
> > >method as above.
> > >
> > >Using either approach, be sure to cover plants that may be exposed 
> > >and capture the gutter drainage if possible to prevent damage to 
> > >plants and grass.
> > >
> > >I was cautioned about pressure cleaning because of potential damage
> > >to the grit on the shingle.  If you choose this approach use as 
> > >little pressure as possible.
> > >
> > >Also be careful walking on the roof.  This stuff gets extremely 
> > >slippery when wet, particularly after you apply bleach.   
> > >
> > >Does it seem to anyone else that roof fungus has gotten worse in the 
> > >last few years?  It does to me.
> > >
> > >By the way I tried method 1 above and it worked fair, not great.  The 
> > >stain is still there, but it's not spreading like before.
> > >
> > >David Williams
> > >NC Division of Pollution Prevention & Environmental Assistance
> > >P.O. Box 29569
> > >Raleigh, NC 27626-9569
> > >Tel:  (919) 715-6527
> > >Fax:  (919) 715-6794
> > >e-mail: david_williams@owr.ehnr.state.nc.us
> > >Web site: http://owr.ehnr.state.nc.us/
> > >
> > 
> 
> David Williams
> NC Division of Pollution Prevention & Environmental Assistance
> P.O. Box 29569
> Raleigh, NC 27626-9569
> Tel:  (919) 715-6527
> Fax:  (919) 715-6794
> e-mail: david_williams@owr.ehnr.state.nc.us
> Web site: http://owr.ehnr.state.nc.us/
>