53
I-800
Specifications for Engineered Wood and
Steel Open Truss Construction (Figure 1):
Concealed Space Area:
The area of the concealed space is not limited.
However, draft curtains (heat collection baffle) or full-height walls must be
provided to limit the maximum localized detection area to 1000 ft
2
. Draft
curtains (heat collection baffle) or full-height walls must be at least
1
/
3
the
depth of the concealed space or 8 inches, whichever is greater, and must
be constructed of a material that will not allow heat to escape through or
above the barrier. This material may be
1
/
4
-inch thick plywood (refer to
Figure 1, Example 1).
Deflector Position:
The vertical sprinkler-deflector clearance to the bot-
tom of the roof deck is 2 inches minimum to 4 inches maximum (refer to
Figure 1, Example 2). The sprinkler must be installed only in the upright
position. The sprinkler deflector must be installed parallel with the plane
of the roof.
NOTE:
There is no limitation by the UL Listing in relation to
frame arm positioning. However, Victaulic prefers the frame arms to be
parallel with the trusses; this positioning produces a more efficient spray
pattern during sprinkler operation (refer to Figure 1, Example 3).
Concealed Space Height (refer to Figure 1, Example 4):
•
Maximum Height of the Concealed Space:
36 inches
•
Minimum Height of the Concealed Space:
12 inches
•
Maximum Roof Pitch:
2/12 (9º)
Specifications for Solid or Composite
Wood Joist Construction Where the
Upper Deck is Filled with Non-Combustible
Insulation (Figure 2):
Concealed Space Area:
The area of the concealed space is not limited.
However, draft curtains (heat collection baffle) or full-height walls must be
provided to limit the maximum localized detection area to 1000 ft
2
. Draft
curtains (heat collection baffle) or full-height walls must drop below the
joist a minimum of 6 inches or
1
/
3
of the total space (whichever is smaller)
and must run laterally with the joist spaced at 25-foot maximum widths.
Draft curtains (heat collection baffle) or full-height walls must be con-
structed of a material that will not allow heat to escape through or above
the barrier. This material may be
1
/
4
-inch thick plywood (refer to Figure 2,
Example 1).
Deflector Position:
The clearance from the sprinkler deflector to the
bottom of the joist is 1
1
/
2
inches minimum to 2 inches maximum (refer to
Figure 2, Example 2). The sprinkler must be installed only in the upright
position. When the Victaulic Model V2502 or Viking Coin (VK900) Specific
Application Sprinkler is used in an installation with a pitched roof and a
flat ceiling, maintain the specified clearances from the sprinkler deflector
to the bottom of the upper deck joist and the maximum height of the pipe
run to the ceiling in all locations. The sprinkler deflector must be installed
parallel with the plane of the roof.
NOTE:
There is no limitation by the UL
Listing in relation to frame arm positioning. However, Victaulic prefers the
frame arms to be parallel with the joists; this positioning produces a more
efficient spray pattern during sprinkler operation (refer to Figure 2, Exam-
ple 3).
I-800 2755 Rev_I.fm Page 53 Tuesday, September 13, 2005 8:46 AM