FEMA P55 Coastal Construction Manual, Fourth Edition - Mad Cad

Volume II Designing the builDing envelope 11
in Figure 11-36. When laminated shingles are used, high nailing may miss the overlap of the laminated
shingles; if the overlap is missed, the nail pull-through resistance is reduced (see Figure 11-37). High nailing
may also infuence the integrity of the self-seal adhesive bond by allowing excessive deformation (ballooning)
in the vicinity of the adhesive.
Te number of nails (i.e., four versus six) and their location likely play little role in wind performance as
long at the shingles remain bonded. However, if they are unbounded prior to a storm, or debonded during
a storm, the number and location of the nails and the shingles’ nail pull-through resistance likely play an
important role in the magnitude of progressive damage.
COASTAL CONSTRUCTION MANUAL
Figure 11-36.
Proper and improper
location of shingle
fasteners (nails). When
properly located, the nail
engages the underlying
shingle in the headlap
area (center nail). When
too high, the nail misses
the underlying shingle
(left nail) or is too close to
the edge of the underlying
shingle (right nail)
Figure 11-37.
Proper and improper location of laminated shingle fasteners (nails). With laminated shingles, properly located
nails engage the underlying laminated portion of the shingle, as well as the headlap of the shingle below (right
nail). When too high, the nail can miss the underlying laminated portion of the shingle but engage the headlap
portion of the shingle (center nail), or the nail can miss both the underlying laminated portion of the shingle and
the headlap of the underlying shingle (left nail)
11-35