Better Air Flow May Cure Condensation
To the Editor:
I have some additional thoughts about the window condensation
problem in the May
2003 Q&A. Every time I have seen a condensation
problem, it was eventually tracked to an air flow problem. I
have seen such problems in cases where the air flow in front of
the window was blocked too effectively, such as by mini blinds
that fit real well in the opening and were closed up all the
way. Leaving the blinds a tiny bit open allowed the area to
breathe and eliminated the condensation.
I have also seen such problems where steam from either cooking
or a shower would naturally flow into the area of a window or
skylight. Turning on the stove vent hood or bathroom exhaust
fan when steam was being created cured those issues pretty
Home Inspection, Licensed GC
Los Angeles, Calif.
More on Hip Framing
To the Editor:
Thanks to Joe Fusco, Dave Holbrook, and the rest of you at JLC
for the article
"Laying Out a
Split-Pitch Hip" (4/03). It has helped me to refine my
thoughts when preparing a layout. I'd also like to offer some
comments about the article.
I don't understand why the "Partial Roof Plan" on page 87
displays the "Unequal overhangs" label when it becomes evident
later that the goal is to create an equal overhang. Also, the
diagram on page 90, labeled "Solution," clearly depicts equal
overhangs with level fascias. These were correctly achieved,
simultaneously, by multiplying the difference in pitches by the
length of the overhang, expressed in feet. Therefore, the
statement at the top of page 91, "the overhangs will be
unequal," misleads the reader. Instead, this section only seeks
to determine how far the hip must shift off the corner and how
far the ridge extends from a typical 45-degree hip.
The jack rafters on the end are already "shifted out" when the
additional 3 inches of plate material are added, even though
the birdsmouth hasn't actually moved off the wall.
Here's how I would lay out the same roof plan:
1. I would determine the pitch rise of the 8/12 side. The run
is 15 feet x 8 inches = 120-inch rise. This rise would be the
same for the 8 and 10 sides.
2. The 10 side will require 12 feet of run to rise to the same
height, since 12 feet x 10 inches = 120 inches.
3. This run establishes a preliminary ridge end point at 12
feet off the outside of the end wall.
4. Next, I would calculate the plate differential required to
level the fascias at 18 inches, as described on page 90. I need
to be certain to maintain the same rafter depth at the
birdsmouth when I cut on the two different pitches.
5. However, if I raise the plate 3 inches on the end wall and
cut a 10/12 rafter based upon the 12-foot run in steps 2 and 3,
the rafter end will stick above the present ridge point by 3
6. Therefore, I must reduce the run on the end rafter and
extend the ridge the same distance until those lines terminate
at the same point. This would be determined by finding out how
much run will equate to 3 inches of drop on a 10/12 pitch. The
proportion "10 is to 12 as 3 is to what?" provides the answer:
3 5/8 inches. So my new ridge point is an 11-foot x 8 3/8-inch
run from the end of the house. I lengthen my ridge 3 5/8 inches
and offset the hip from the corner out from the front wall that
same distance. (This is where Mr. Fusco helped me to see how to
calculate the location of the hip. Prior to this we had snapped
lines at full scale to locate the hip on the wall, as described
in an earlier JLC article.)
7. At this point, I still have the familiar 8/12 and 10/12
pitches for my common and jack rafters and only have to
calculate a pitch for my hip. To get the hip run I find the
hypotenuse of a right triangle, triangle A, which has 15-foot
and 12-foot sides. The result is 19.21 feet. Once I convert
that to inches (19.21 x 12 = 230.52 inches), I can express the
hip pitch as the ratio of 120 inches of rise to 230.52 inches
of run and reduce it to something manageable on the framing
square for my cut marks. Reducing by a factor of 10 and
converting from the decimal, this would be about a 12-to-23
8. Then I can calculate the hip length by finding the
hypotenuse of a right triangle, triangle B, with a 120-inch
rise and a 230.52-inch run for its sides. This calculates to be
259.88 inches long.
9. I would calculate jack rafter and plywood cut angles pretty
much the same way as Mr. Fusco, using a calculator and paper
for visualization. I got lost in the backing angle calculation
method and currently use a method suggested by my lead man.
Using a speed square, he noted that if you project the common
rafter pitch through the hip/val reading to the degrees, you
get a reading that works. I don't know why, but it works well
enough for our needs.
10. Now I have to make sure the rafter depth (height above
plate) is the same on all the rafters, and in particular that
this height on the backed hip is located in line with the front
wall 3 5/8 inches out from the corner. Finally, keeping in mind
that all these calculations are point to point and that I have
to adjust for lumber dimensions, I'm ready to cut.
David A. Brothers
Elizabeth City, N.C.
To the Editor:
In the article
"High-Tech Office in
a Truck" (5/03), the author talks about his communication
preferences and says about Nextel that "the walkie-talkies have
a range of over 50 miles in flat areas, but when we are working
in the hills ... reception can be a problem."
Actually, Nextel's Direct Connect, as it is called, is not a
simple line-of-sight "walkie-talkie," but rather a two-way
radio that uses the same towers as Nextel's mobile phone
service. The range is basically limited only by your local
calling area. Nextel is in the process of even expanding this
to include the entire United States.
Curtis O. Seebeck
San Marcos, Texas
Performance Guidelines Come in
To the Editor:
The article "Trade
Standards" (Legal, 4/03) discusses two implied warranties,
fitness-of-purpose and workmanlike manner. The first is
basically covered by any good local building inspection. The
author suggests handling the second, workmanlike manner, by
comparing your work to the "community standard of quality." I
feel this is a poor approach. The homeowner could find a dozen
builders or crew chiefs to support their side, and likewise the
remodeler in question.
I take care of small issues and quality concerns without
batting an eye. I find this goes a long way with my clients and
puts me on top of the list of contractors they call for their
next project. Plus, the word-of-mouth advertising that comes
from this attitude toward service is immeasurable.
For those few clients who seem determined to get a reduction
in the final payment and feel they can use the quality of my
work as justification, I use published quality guidelines. My
customer agreement states that all projects I complete conform
to the Residential Construction Performance Guidelines
published by the NAHB. Recently that $6 investment quickly
resolved an issue with a prefinished hardwood floor. The
guidelines provide a way to measure quality, determine
corrective measures, and have a brief "discussion" to help
educate clients. For example, this section about wood flooring
talks briefly about the fact that shifts in humidity will
affect the size of gaps between boards.
My clients walk away feeling much better about the work I've
completed. And I walk away with my full final payment and a
client that I'm confident will use me again.
Steve's Home Improvements