Page 16 - Green Builder's Resilient Housing Design Guide 2018

Building Flaws and Their Solutions

1

Design wind loads used were too low,
Shiners – Staples resulting in members and connections too
weak for the winds encountered, and roof

CREDIT: FLORIDA DIV. OF EMERGENCY MANAGEMENT and framing damage.
Bent Strap HIS IS PRIMARILY A PROBLEM with older homes built before codes

Top of were improved, subject to the rigors of corrosion (see page 21) or poor
workmanship, especially in homes where two structural systems are
combined. A common failure point in high winds, for example, has
Concrete Wall T been the weak linkage between concrete masonry walls and engineered
truss roof systems. As Florida’s Division of Emergency Management notes, “the

of the block, often with only a few widely spaced anchors. Rafters were then
toenailed to this face plate. For new and retrofits, this plate must be attached by
Weak link. This thin metal strap is not enough to vast majority” of older CMU homes simply had a 2 x 8 plate attached to the top
hold a truss rafter to a masonry wall in a big storm. embedding anchor bolts of a half-inch or larger diameter, spaced no more than 48
inches. The bolt must be installed within a couple of inches of the end of any plate.
Also, washers and nuts must fit without gouging out the wood. I would recommend
stainless steel anchors (see item No. 6).

2

Degradation of building elements
and connections due to material
deterioration, insect infestation

or lack of proper preventive
maintenance resulted in premature

building and envelope system failure.
I
WOULD CLASSIFY THIS AS THE NO. 1 ISSUE of concern in
hurricane-threatened regions. The Insurance Journal notes that
the age of a home has a direct correspondence to the level of
damage inflicted by a hurricane. Homes in Florida built between
1994 and the 2001 code upgrade, for example suffered much
more than newer homes. But homes built prior to 1994 fared even more
poorly. Hurricane Andrew in 1992 destroyed 125,000 Florida homes. Age matters. Older building materials and systems perform much more
An important consideration for the future is the intermixing of new poorly in high wind than new products built to better codes.
and older homes. A 30-year-old property can literally blow to pieces in
a storm, and all of its components, such as roof tiles, 2 x 4s and plywood, become airborne projectiles. And that’s not even considering the
force of a home carried off of its foundation by storm surge flooding. Some areas of Florida are designated as a windborne debris region,
where new homes requiring impact glass and other features.
The best defense is to build the home as we’ve suggested here, with corrosion-resistant materials, sufficient high-quality fasteners and
straps, with the goal to make future homes much more able to maintain their hurricane resistance than their predecessors.

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