Condo Media - January 2018 - 49

Helpful Advice Decking
between the deck ledger and building
band joist. The deck collapse tragedy
of the Library Gardens Apartment in
Berkeley, CA, where six died and seven
were severely hurt resulted in an early
release of approved deck inspection
protocols in the 2018 International
Building Code.
The U.S. Forest Products Laboratory completed a study of five years of
newspaper articles from around the
country reporting collapsed decks and
showed "nearly every collapsed deck
had been attached with nails, rather
than bolts, and investigators had
pinpointed nails as the cause of the
collapse."
Thirty years ago, many decks were
attached to buildings using nails that
rust away or simply do not have the
lateral holding power of bolts. To
make matters worse, developing problems are often not noticed in a casual
visual inspection because the ledger
board is hidden behind the siding. This
problem is compounded by past deck
building practices not protecting the
ledger due to a lack of adequate flashing. New England's salty air can create
some very corrosive chemistry on deck
components.
INSPECTION PROGRAM
GUIDELINES
So what is the maintenance committee
to do? First, organize an inspection
program for your older decks, porches,
or balconies either with internal voluntary help, your property manager,
or a competent outside company. The
International Code Council (ICC)
recommends condominiums inspect
decks twice a year. Look for split or
rotting wood, loose or missing nails,
screws, or anchors where the structure
is attached to the building, missing,
damaged, or loose support beams and
planking, and wobbly handrails or
guardrails. This may require removing
siding, but it is necessary.
This type of invasive inspection is
especially important for stacked decks
on mid-rise type buildings. Often,

these decks are enclosed on their
perimeter and underside in order to
provide a pleasing appearance and
to keep rain from flowing from one
deck to another. Even with waterproof
membranes in place, moisture can enter enclosed deck spaces and without
adequate air venting, even the strongest deck girder and joist components
can deteriorate and fail leading to
serious accidents.
The deck inspection should confirm:

1
2
3
4

Only weather resistant fasteners including joist hangers and
anchor straps are used, such
as hot-dipped zinc-coated
galvanized steel, stainless steel,
silicone bronze, or copper.
Guard rails should be a minimum of 36 inches high with
balusters spaced less than 4
inches apart. Note: guard rails
and handrails are not necessarily the same thing. Handrails
should be continuous with no
interruptions such as newel
posts and have 1 1/4 to
2 inch diameters.
Deck girders should never
be bolted to the sides of deck
posts. Rather, they should be
supported on top of posts with
a galvanized post-to-beam connector.
Diagonal structural deck
components should never be
toe-nailed, but rather bolted.

REPAIR AND REPLACEMENT
The next step of course is to develop
a plan to repair or replace the deficiencies found. There are a variety
of resources available to do independent research, but often bringing a
professional in at this time can save
both time and money. Not only do the
codes keep changing, but many local
code enforcement officers have their

own preferred ways of deck building
and it would be wise to find out what
those ways are.
However, for those adventurous
committee members who want to
find their own answers, I recommend
they download the PDF version of the
Prescriptive Residential Deck Construction Guide found through Google.
Though this is not a building code, it
helps to explain the nature of safe deck
building and can serve as an invaluable
supplement. As deck inspection is so
complicated, researchers at Virginia
Tech produced the Manual for the
Inspection of Residential Wood Decks
and Balconies. This manual was published by the Forest Products Society
in cooperation with the ICC.
Perhaps the most challenging aspect
of deck repair or design is once you
resolve the structural issues you are
still faced with the ever-increasing selection of deck materials and products.
Twenty-five years ago, selecting pressure-treated timber was the standard
for both the framing and deck boards
for many common decks. This became
less desirable with the concern about
the arsenic-laced treatment chemicals
and the danger to young children and
the environment in general. Today's
less toxic pressure treated lumber has
its own challenges due to its corrosive
effects on galvanized fasteners and
copper flashing.
Though most wood decks use pressure treated frames, today's trends use
deck boards of other types of wood or
wood substitutes. So, the simple deck
is not so simple after all. However,
maintaining a safe deck may be the
simplest and best decision an association can make.
■ JACK CARR, P.E., RS, LEED-AP,
IS SENIOR VICE PRESIDENT WITH
CRITERIUM-ENGINEERS SERVING
ALL OF NEW ENGLAND.

January 2018

49
Condo Media - January 2018

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