Lead Risks Are Real
Thank you for the story "Lead-Safe Remodeling" (9/04).
Unfortunately, while some overreact to this subject, many do
not take it seriously enough. I should know, because I'm one of
the latter.
One month ago, my child was diagnosed with a high lead blood
level, caused by excessive dust from our own home renovation
and exterior painting project. I personally supervised a very
dust-conscious and clean workplace, following all the usual
common-sense tactics. But I did not create true barriers, did
not use a HEPA vacuum, and did not wash surfaces
thoroughly.
Although my daughter's condition is not likely to cause
life-altering damage, it is bad enough to cause this father to
feel extremely guilty and to immediately rethink how I approach
environmental issues. While we as builders should not overreact
to these issues, we should never dismiss them as "crazy
environmental nonsense" or think that these problems are
somebody else's to worry about. These problems are right here
in my own living room, in my air, and on my baby's hands.
Hopefully, others can learn from my mistake.
Anonymous
New York
Effective AC for Humid
Climates
Mr. Akers did a great job of covering many of the critical
elements in his article "Air Conditioning for Humid Climates"
(10/04). I would like to add a couple of comments.
Almost all of the humidity control techniques that Mr. Akers
discussed can result in colder supply air temperatures. The
result can be condensation on supply registers that get
"super-cooled" while the system is running, and end up below
the dew-point temperature of the room air when the system shuts
down. Blowing this cold air directly on a surface can also
result in condensation on, for example, the back of a dresser,
the underside of a table, or clothes in a closet. I also see
problems when two zones on the same system are set to very
different temperatures.
In solving moisture issues, we often end up using auxiliary
dehumidification systems. An AC load in an actual house in
Charleston, S.C., is 47,000 Btu/hr of sensible (heat) and 7,000
Btu/hr of latent (moisture) in the middle of the afternoon when
it is 92 degrees out, but only 1,000 Btu/hr sensible with the
same 7,000 Btu/hr latent load first thing in the morning when
it is 75 degrees outside. (The temperature of the outside air
has changed, but the amount of moisture in the air has
not.)
To attempt this with AC equipment, we tailor things as
outlined by Mr. Akers. We basically make the supply air colder,
which removes more moisture but cools the house a little too
much. Some AC controls limit overcooling to 3 degrees below the
thermostat setting, but at 3 degrees colder we need to remove
even more moisture to get to our desired relative humidity
level. And at some low fan speeds, we don't get good mixing of
the air, which leads to other issues.
Most of the time we luck out and the outside temperature jumps
up, so we get more sensible load. But in spring and fall, and
on rainy or cloudy summer days, we can get extended times with
a high moisture load and minimal sensible load. Under those and
other part-load situations, I find it much more effective to
add in a whole-house dehumidifier. Today's AC equipment is
great at controlling inside temperatures. A dehumidifier is
great at controlling humidity. With both, we can actually
really control temperature and humidity.
Craig DeWitt, P.E.
RLC Engineering
Clemson, S.C.
Stray Voltage Problem
Resolved
Reading the article "Stray Voltage Zaps Homeowners" (10/04)
was like reading my own story. I have an in-ground swimming
pool that was installed in 1990, with everything done to code.
Over the last six years or so, we noticed that when swimmers
touched both the pool water and the reinforced concrete deck
around the pool or the pool ladders, they would get a little
electric jingle, felt primarily at the surface of the pool
water. It was not overly uncomfortable, but, needless to say,
water and electrical shocks make people uneasy. I dreaded
closing the pool each fall because as I would blow the lines
out to seal them, the concrete deck would get wet, and as I lay
on the wet concrete trying to cap the return lines, my arm
would tingle from the electric shock.
I talked to electricians on numerous occasions and had an
electrician review the system; the pool wiring checked out. We
talked to the power company several times and they always
stated that our wiring system was at fault. What confused me
was that even after pulling the circuit breaker for the pool, I
would still receive the jingle.
Finally, someone from the power company agreed to come and
look things over. Lo and behold, they found there was a problem
with their transformer setup at my power pole, which is 200
feet from the house. I have underground cable from the pole to
my service entrance. They sent someone back the following day,
made a quick and simple change, and my stray-voltage problem
disappeared. It was a confusing, frustrating problem that
lasted for more than six years, but thankfully it is now
gone.
The article leads me to think that the situation may have
developed over time because of the growth that my local town
has seen over the last 10 years. The power demands are now
substantially larger than they were when the pool was built,
and that may have been the source of the stray voltage.
Jay S. Meunier, Estimator
Pizzagalli Construction
South Burlington, Vt
Code Correction
In the article "Resisting Tornado Damage" (10/04), the drawing
on page 147 indicates that the 2003 IRC requires trusses to be
connected to the top plate with two 16d toenails. But Section
R802.10.5 requires that trusses be connected to the top plate
with approved connectors having a resistance to uplift of no
less than 175 pounds.
Kurt Albrecht
Green River, Wyo.
Supporting Safety
Thank you for bringing to the attention of your readers the
importance of building to the requirements of the International
Residential Code and local codes. Your October 2004 articles
"Hurricane Charley's First Lessons," "Hurricane-Rated Windows,"
and "Resisting Tornado Damage" demonstrate two major benefits
of building to code: saving lives and reducing property losses.
Unfortunately, too often the perception of codes is more in
line with your article "Amid Apprehension, Code Comes to
Pennsylvania."
Congratulations on a great issue and thank you for your
support of building safety.
James Lee Witt, CEO
International Code Council
Energy Ratings of Impact-Resistant
Windows
I read the October article on hurricane-rated windows with
interest. The article never mentioned the energy performance of
these windows, other than that some add a second layer of
glass. Are they available with low-E coatings? What sort of
NFRC ratings for U-value and solar heat-gain coefficient do
they carry? What are the cost implications of these
enhancements and how available are they?
Richard Faesy
Vermont Energy Investment Corp
Bristol, Vt
Author Charles Wardell responds: While
all impact-resistant windows have to meet state and local
energy codes, many companies go beyond the minimum
requirements. According to Bill Lazor of Simonton Windows, for
example, all of that company's impact-resistant units can be
ordered as Energy Star-compliant anywhere in the country. They
are available with a hard-coat low-E coating. The U-value for a
double hung is .33 (total unit value, not center of glass); the
solar heat-gain coefficient is .99. For typical units, energy
enhancements might add around $20 per window.
Cupped LVL
In the August 2004 Products, there was a product evaluation
conducted on the FastenMaster TrussLok screw manufactured by
OMG of Agawam, Mass., which was developed specifically for
engineered wood products. The article indicates that the screws
work well to pull cupped LVL together. Although this may be
true, this practice is discouraged and should not be
promoted.
Cupped wood is often caused by a difference in moisture
content from one side of the wood to the other. Using screws or
bolts to flatten or pull cupped wood members together induces
cross-grain stresses, which can cause splitting. Cupping can be
reversed by allowing the moisture content to equalize, but this
is not always practical. Proper handling and storage will
reduce cupping.
Michael Collins, P.E
Trus Joist
Boise, Idaho
Of Mice and Cats
Regarding the Q&A "Mice and Insulation" (10/04): Get a
cat, or maybe two, if it's a real problem (two will keep each
other company). You don't have to really love them that much;
think of them as "working cats." Like a cattle dog or milk cow,
they're there to do a job.
If after a month you still have mice, you're feeding the cats
too much cat food. Don't feed them milk or canned cat food;
stick to the dry cat food. Cats don't need to come indoors,
either. They'll solve the problem before it reaches the
house.
Johnny Lawrence
Rocky Mount, Va
Paul Fisette gave a good answer on where to find information
about radon and fixing radon problems (Q&A, 9/04). At
the site Paul mentioned, www.epa.gov/radon/pubs/, there's a
good publication, "Building Radon Out," that describes how to
prevent radon problems in new construction. This is important,
because it's more difficult and expensive to fix a radon
problem after the fact. The booklet is full of great
information, architectural drawings, and step-by-step
illustrations, and is available for free.
Mike Rogers
Waterville, Maine
Bore Buster Price Correction
Unfortunately, the $500 price for the
L.J. Smith Bore Buster kit quoted in the article
"Stair-Building Tools" (12/04) is a wholesale price. You'll
have to check with your local suppliers for retail sales. The
kit comes in a couple of versions starting at around $900
— a big investment unless you do a lot of stairs.
— The Editors
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