8
Obstructions
Obstructions to Attic Sprinklers™ differ from standard sprinklers and the following criteria shall be used.
There can be up to a 6" obstruction, measured vertically, as long as it is 36", measured vertically, below the Attic
Sprinkler. If the obstruction is closer or larger, there must be a sprinkler on the other side of the obstruction. See figure
A & B. This does not limit the top cord of the trusses or the depth of the rafter, but rather obstructions that run across
the trusses or rafters.
Figure B
Figure A
6" max.
No
Sprinkler
Required
36" min.
If the obstruction is below the sprinkler, there must be 6" clearance over the top of the obstruction to allow water to pass
both over and under the obstruction. The 6" is measured perpendicular to the slope from the bottom of the joist. If
there is not 6" clearance, a sprinkler must be added on the opposite side of the obstruction.
Figure D
Figure C
6" min.
36" min.
less than 6"
36" min.
Figure F
Figure E
36" min.
≤
4'-0"
No Sprinkler
Required
Ducts, as per NFPA 13, require a sprinkler under
them if they are over 4'-0" wide. If they are not, then
no sprinkler underneath is required.
For Vertical Obstruction, See Table 1 on Page 9.
The maximum dimension of the obstruction is the
width of the obstruction and the horizontal
distance away from the obstruction is measured
flat.
See Table 1
over 6"
Sprinkler
OBSOLETE
