[Greenbuilding] Rigid foam on an old house

[John E. Beeson]

Wayne,

Sorry, I'm not addressing your major issue, but something else.  I
realize this is off-topic to what you really want to accomplish, but
really, you can't go too wrong adding more insulation to your home.  The
cedar shingles are rotten because of no air space behind.  Set up a rain
screen (see www.buildingscience.com and search the papers).

Ok, but to my post:
I would opt to not put on vinyl siding.  Please.  Not just because of
the article posting earlier: people with vinyl siding face increase in
insurance rates.

But because vinyl is a poor choice material - it can't be recycled!  In
addition, vinyl chloride itself is a carcinogen, and the phthalates that
PVC contains are indicted as both carcinogens and hormone disruptors.
Dioxin, produced when PVC is burned and when it is produced, is one of
the most toxic chemicals known. When PVC burns, hydrogen chloride is
created, deadly to occupants and firefighters because it is colorless
and heavier than air. Because PVC is so friendly to additives, there are
lots of added undesirable materials such as lead and cadmium, which may
actually leach out of the plastic. We have banned lead paint, only to
replace it with lead from vinyl siding.  

The USGBC just released a report on the use of vinyl in 'green'
buildings and in summary, considering alternatives to it, there aren't
any.
http://www.buildinggreen.com/auth/article.cfm?fileName=160302a.xml

And there is this followup worth noting:
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USGBC Supports Screening of PVC
Letters - Environmental Building News May 2007

Much has changed in the U.S. Green Building Council's Technical
Scientific Advisory Committee [TSAC] final report on PVC [see EBN Vol.
16, No. 3]. In this round, TSAC expanded its analysis to account for
life-cycle issues that traditional LCA (life-cycle analysis) tools often
miss, such as disposal issues and occupational exposures, and found that
PVC leads to the release of dangerous quantities of dioxin and other
carcinogens. The report authors specifically found that "when we add
end-of-life with accidental landfill fires and backyard burning, the
additional risk of dioxin emissions puts PVC consistently among the
worst materials for human health impacts."

TSAC looked at a range of health and environmental impact indicators and
provided in its report a low, average, and high estimate for each
category. Predictably, the results vary depending upon which estimates
are used. Even using the low-end estimates, PVC is rarely superior in
any product type. Low-end estimates are not, of course, protective of
human health. Taking a precautionary principle approach to examining the
report's data using the average and high estimates of impact for all
materials leads to the following conclusions:

* In the report's cancer ranking, PVC is consistently the absolute worst
for each of the four product types studied. On the report's total human
health ranking, PVC consistently comes out either tied for worst or
absolute worst.

* In the report's environmental ranking, PVC's performance is
mixed-still absolute worst in the case of flooring, compared with both
VCT and sheet vinyl-but better than one alternative and roughly equal to
the other alternatives in the other three cases studied. Specifically it
ranked better on environment than cast-iron pipes, aluminum siding, and
aluminum windows and not significantly different from ABS pipes, wood
windows, wood siding, and fiber-cement siding.

Overall one can conclude that screening out PVC will lead to
consistently better cancer and overall health results. Other
environmental impacts will vary depending upon the material chosen,
requiring other screening approaches.

Instead of recommending a specific credit on PVC alone, the report
recommends issue-based credits, specifically suggesting "comprehensive
approaches to issues such as bioaccumulative pollutants," an approach
that has been gaining momentum in healthcare green design in recent
years, screening out materials based on a suite of persistent
bioaccumulative toxicants, like dioxin, halogenated flame retardants,
heavy metals, and perfluorocarbons.

The report represents an important step for the Council and LEED in
signaling the importance of addressing health issues and precaution
across the full life cycle of materials.

Tom Lent, Policy Director
Healthy Building Network
Washington, D.C. 

QUINN EVANS | ARCHITECTS

John E. Beeson, LEED AP

219 1/2 N. Main Street
Ann Arbor, MI  48104
jbeeson at quinnevans.com
www.quinnevans.com
v 734 663 5888
f 734 663 5044
P Before printing, think about the ENVIRONMENT