Deck Ledger Bolting Schedule Wends Its Way
Into the Code
Offcuts
Pump Truck Accident Leaves Worker
Dead
Green Builders Convene in San
Francisco
Every year, dozens of residential decks come crashing to the
ground across the country. According to Frank Woeste, professor
emeritus of wood engineering at Virginia Tech and a passionate
advocate of safely built decks, "Except for hurricanes and
tornadoes, more injuries and deaths may be connected to deck
failures than to all other structural failures stemming from
typical residential code loads, including seismic and snow
loads."
And yet there is very little in the building code that directly
addresses deck structure. "With respect to the structural
integrity of a deck," says Woeste, "there are only two numbers
in the IRC: 40 pounds per square foot, the occupancy live load;
and the 200-pound concentrated load, which relates to the
guardrail. That's it. Other than the fact that the code now
says you can't use nails in withdrawal, those two numbers are
the only guidance given related to design for resisting gravity
loads. The problem is there's no way for a contractor to
translate a number like 40 pounds per square foot into ledger
bolting requirements on a project."
Two men working on a deck in Chattanooga, Tenn., sustained
serious injuries when it came down in May; the grandmother of
one of the men had stepped back inside the house moments before
the collapse.
That may change with the 2009 IRC, if a ledger bolting table
that Woeste and his colleagues at Virginia Tech and Washington
State University have developed makes it through the code
approval process. The ledger attachment proposal was heard at
the recent International Code Council annual meeting in
Orlando, Fla., which concluded October 1. The proposal,
RB159-06/07, passed "as approved"; it can still be amended
before becoming code in 2009.
Woeste has worked on the ledger issue since 2003, when he
— along with fellow professor Joe Loferski and former
graduate student Cheryl Anderson — published the article
"Attaching Deck Ledgers" in JLC (8/03), which included ledger
attachment schedules developed using conventional connection
design methods.
One child and three adults were injured when this
Chesterfield County, Va., deck collapsed in June (top). Three
of the victims were treated at the hospital, one with a head
injury caused when she struck the brick patio below. A rotted
band joist was the clear cause (bottom).
The results of the engineering calculations included bolt and
lag screw spacings that were glaringly conservative — 2
to 3 inches in some cases. Predictably, JLC readers expressed
skepticism, so Woeste and team took a different tack and tested
the ledger connections to failure in the lab using calibrated
equipment.
The results of those tests were published in JLC in March 2004
("Load-Tested Deck Ledger Connections") and became the basis
for the current code proposal. The original data was valid only
for pressure-treated southern pine ledger boards, which are
common in the East.
That limitation was addressed when former Woeste student Don
Bender, now a professor of engineering at Washington State,
replicated the tests using pressure-treated hem-fir, a common
western species. Though hem-fir is less dense than southern
pine, the test results were nearly identical, essentially
confirming the earlier numbers and yielding a bolting schedule
that is useful coast to coast.
JLC requested that in addition to the usual single shear
connections, where the ledger is attached tight to the rim
joist or sheathing, Woeste include a ledger connection with a
half-inch drainage space — a detail commonly used in New
England and the Northwest, where rain and snow can penetrate
behind ledger flashings and attack the band. The "cantilever"
effect had only a slight effect on the bolt spacing.
To view the proposed ledger table in its entirety, go to
www.jlconline.com/deckledgers. —
Don Jackson
Offcuts
• Colorado builders who have a comprehensive
general-liability policy in place during construction are
covered even after the home has been sold, the state's Court of
Appeals ruled in June. Village Homes of Colorado, a builder,
had been sued by homeowners because of damages from expansive
soil; when the company submitted the damages to Travelers
Casualty and Surety Co., the claim was denied because it came
after the policy ended. However, the court ruled that the
damage occurred during construction and while the policy was in
effect. Although the decision limits the time frame in which
homeowners can file a claim, it essentially gives builders
extended protection.
• Responding to questions about a 6 percent increase in
construction-site burglaries, Charlotte, N.C., police suggested
that part of the problem might be solved if builders delayed
appliance installation. Andy Leonard, a captain in the
Charlotte-Mecklenburg police department, told the Charlotte
Business Journal that if contractors "waited until 24 hours
before the closing to install appliances, it could have a
significant impact."
• With real estate prices so high, some homeowners looking
for extra space have been doing away with pitched roofs. By
switching to a flat roof, they gain a floor without exceeding
height restrictions. However, this trend has already earned
itself a backlash: Community members who argue that these
modifications ruin neighborhood aesthetics are pushing for
minimum-roof-pitch requirements. The town of Bethany Beach,
Del., for example, instituted a minimum 7/12 pitch for houses
that reach the jurisdiction's maximum 35-foot height. The
change came in response to a number of renovations done by
investors looking to get more floor space in houses they
intended to resell or rent out.
• Frustration with the cost of coastal insurance isn't
just a problem in the Southeast. Connecticut insurance
commissioner Susan Cogswell declared a 90-day moratorium on new
underwriting guidelines, including increased rates, starting
September 7. Her move was in response to consumer outrage after
the Andover Co.s announced plans to cancel policies in
Connecticut if homeowners didn't install storm shutters over
all openings. Other insurers have instituted similar
requirements that also affect policyholders.
• A Pennsylvania court struck down an ordinance requiring
fire sprinklers in all new-construction and renovation projects
of more than 1,000 square feet. Schuylkill Township had enacted
the ordinance in March 2005; it was overturned in September,
reports the Central Penn Business Journal. The decision was
based on the state Uniform Construction Code's requirement that
unique local conditions must be identified for local ordinances
to exceed the UCC. The Pennsylvania Builders Association hailed
the ruling as a victory for affordable housing.
• Although Chinese cedar — which is actually a
member of the bald-cypress family — is marketed in the
United States as an inexpensive alternative to western red
cedar, members of the lumber industry disagree on its quality
as a material. While some argue that it's a better wood than
western red cedar, with fewer and tighter knots, others say
it's inferior because it's kiln-dried and subject to swelling
in rain. A recent study at Oregon State University seems to
bolster the species' credentials: According to industry
newsletter Random Lengths, researchers say the wood shows a
cedar-like resistance to rot.
Pump Truck Accident Leaves
Worker Dead
A concrete pumping truck capsized on a residential
construction site in northeast Madison County, Miss., killing a
construction worker who was pinned beneath the boom. The
September 15 accident is still under investigation, according
to Clyde Payne of the OSHA area office in Jackson, Miss. The
investigation will focus on whether the boom truck's outriggers
were set properly, or whether one of them failed. Payne did not
say when he expects the investigation to be complete, but he
promised to contact JLC with the results.
This concrete pump truck tipped over on a job site in Lake
Caroline, Miss., pinning a worker beneath the boom. OSHA is
investigating.
According to a safety bulletin published by the American
Concrete Pumping Association, setting the outriggers is a
critical part of the boom operator's job, but the general
contactor also has an important role to play in ensuring a safe
outcome on any pumping job.
A wrecker crew prepares to right the capsized pump
truck.
For example, the GC should be certain to order the correct boom
size. If the boom is too small, the truck may need to set up
close to the foundation, over disturbed soil. If it's too
large, more cribbing may be needed under the outriggers to
spread the load, increasing setup time and expense.
The GC should also have an open area ready for the pump before
it arrives, and should make the boom operator aware of any
patches of soft or disturbed soil, as well as any underground
utilities.
Finally, the GC should monitor the job to make sure the boom
operator takes no chances.
The ACPA's bulletin, "Setting Outriggers to Prevent Accidents,"
is available for download at
www.concretepumpers.com . It provides
excellent information for anyone involved in a concrete pumping
job: contractor, dispatcher, and operator. —
D.J.
Green Builders Convene in
San Francisco
More than 6,000 people attended the first annual West Coast
Green residential building conference and exposition in San
Francisco in September. The three-day event, which showcased
the latest green and healthy building products and
resource-efficient materials, attracted a diverse crowd:
architects, builders, engineers, green-movement activists, and
representatives of government and nonprofit housing
agencies.
Green appeal. In one of the more interesting
business-oriented presentations, Marc Richmond of Practica
Consulting spoke about how to market yourself as a green
builder. Only 5 percent or so of the market, he said, is
committed to green principles and will buy something because
it's green. Of those who do hire green builders, only 40
percent want to discuss payback and only 10 percent actually
care about it. So why are people buying green stuff? Because,
Richmond explained, "it's cool, high-tech, or their neighbor
doesn't have it."
In a room filled with green advocates, Richmond made the point
that being a green-building professional is not about
ideological purity: You still have to give customers what they
want. "Let them buy your green stuff because it's cool. Don't
make the mistake of trying to sell your product or service [to
customers] for the same reasons you would buy it."
Forget the hair shirt. In a
presentation on green remodeling, a panel of remodelers
recounted their efforts to integrate green building principles
into their business. "I don't believe in the hair-shirt
mentality of green," said Michael McCutcheon, of Berkeley,
Calif., referring to the all-or-nothing thinking often
associated with green building. "We do what we can. We start
where we are and if we can do 10 percent better, great. If we
can do 20 percent better, that's great, too."
McCutcheon warned against material vendors who push the green
qualities of their products to the exclusion of all else:
"Watch out for people who are just telling you it's green. It
still has to be durable, it has to be high quality, they have
to deliver it on time, and it has to be what you ordered." And
he pointed out that even if a material is "certified," it isn't
green if you can't use it and it goes to waste.
Greening your company. Builder Dennis
Allen of Santa Barbara, Calif., spoke about the importance of
getting field employees to buy into green building. His company
offers training and financial incentives, including a program
that encourages supervisors to replace large trucks with
hybrid, biodiesel, or other low-polluting, fuel-efficient
vehicles.
Performance testing. On the technical side,
performance testing was a key theme in discussions about
building science and the efficiency of hvac and water-heating
systems. Or, as speaker John Proctor, a consulting engineer,
put it: "If you don't test, how do you know you did it
right?"
Walking the floor. On the expo floor,
some 250 booths displayed a broad array of products, among them
such relatively conventional wares as spray-
in-place insulation products, ICFs, and SIPs. Manufacturers of
photovoltaic power systems also exhibited.
Alternative products — which at a traditional industry
event might account for one or two displays — took up a
large portion of the show floor. There was a profusion of
millwork — flooring, doors, cabinets, trim — made
from reclaimed lumber, as well as bamboo flooring, recycled
cotton insulation, wool insulation, "organic" paint, knobs and
tile made from recycled glass, rainwater-catchment systems, a
pine-tree resin and aggregate paving product, and a countertop
material made from recycled paper.
Nearly as unusual as some of the products — at least by
building-show standards — were the concessions, which
featured mostly Indian and Middle Eastern food with a heavy
emphasis on vegetarian fare. Maybe next year I'll try the vegan
corn dogs. — David Frane