[Greenbuilding] Radon

[RH Irving Co Inc.]

Anybody know why radon vents have to be 4"?  A 3" pipe will fit thru a
standard 2x4 wall; a 4" pipe requires a 2x6 wall (more lumber) and limits
the possible locations.
Bob Irving

-----Original Message-----
From: greenbuilding-bounces at listserv.repp.org
[mailto:greenbuilding-bounces at listserv.repp.org] On Behalf Of Kidd, Peter
Sent: Wednesday, July 04, 2007 10:44 AM
To: Lawrence Lile
Cc: greenbuilding at listserv.repp.org
Subject: Re: [Greenbuilding] Radon

CMHC brought out a new guide for Canadian homeowners, but its info is
not really exclusive to Canada.
www.cmhc-schl.gc.ca/odpub/pdf/61945.pdf


-----Original Message-----
From: greenbuilding-bounces at listserv.repp.org
[mailto:greenbuilding-bounces at listserv.repp.org] On Behalf Of Lawrence
Lile
Sent: Tuesday, July 03, 2007 2:55 PM
Cc: greenbuilding at listserv.repp.org
Subject: [Greenbuilding] Radon

 
I've recently had to go through radon testing in some rental houses, and
learned a lot in the process. 
 
Radon relates to Green building because radon is an insidious indoor air
pollutant.  Tighter houses that began to be constructed in the 1970's
began to concentrate indoor radon more than old leaky ones did.
Awareness of this problem is not more than 30 years old, and really in
the last ten years has it been even considered widely. 
 
Radon was discovered as a problem in homes when a nuclear plant worker
inadvertently wore his radiation dose badge home. His house was hot!
After the guys in moon suits, who figured he'd brought home some
radioactive material fromt he plant, got done, they realized his house
had a high level of naturally occurring radon, which is radioactive.
Then they tested his neighbors house, and it was hot, and tests houses
throughout the town, and a big fraction were hot, and within a few years
realized there was a national problem.  
 
OK how big a problem?  A smoker, who lives in a house with 20 pC/L of
radon for many years, has a risk of 250 per 1000 of getting lung cancer.
That's pretty bad!  The risks go down for nonsmokers, and go down even
more for lower levels of radon.  4 pC/L is the minimum action level,
where lung cancer risks are not much different than where there is no
radon.  
 
Any new construction *should* have at least a passive radon reduction
system installed (so-called "radon-ready") and have a radon test after
construction is complete.  There are no laws or codes about this, but it
is becoming common to see buyers requiring radon tests.  It is a lot
easier to build during construction than to retrofit.  I would consider
it a vital part of a Green home.  
 
We installed an active radon reduction system last weekend.  It was
actually quite simple - a pipe to the gravel under the slab, 4" PVC
(shudder) pipe to a small, low power fan, and then an exhaust pipe to a
bird screen up under the eaves.  Slap on a label, and there you go.
Contractors charge $1000 to $2000 for such a system, which uses about
$200 in parts.  
 
I was surprised how much air was blowing out the top of the exhaust
pipe.  There must be quite a number of cracks under a typical older
slab, to allow air to flow so freely.  There is probably a big hole
under the tub, and gaps at some plumbing penetrations, as well as cracks
int he basement floor and around the edges.  
 
Lawrence Lile
_______________________________________________
Greenbuilding email list
List info:
http://listserv.repp.org/mailman/listinfo/greenbuilding_listserv.repp.or
g
List email: Greenbuilding at listserv.repp.org Managed by BuildingGreen,
Inc. http://www.buildinggreen.com
      publisher of Environmental Building News and GreenSpec(r) Hosted
and archived by REPP / CREST http://www.crest.org

_______________________________________________
Greenbuilding email list
List info:
http://listserv.repp.org/mailman/listinfo/greenbuilding_listserv.repp.org
List email: Greenbuilding at listserv.repp.org
Managed by BuildingGreen, Inc. http://www.buildinggreen.com
      publisher of Environmental Building News and GreenSpec(r)
Hosted and archived by REPP / CREST http://www.crest.org