I have an obstruction question regarding what I feel is a gray area of NFPA 13. I'm looking at obstructions greater than 18 inches below sprinklers.
NFPA 13 states that any obstruction over 4 ft wide requires sprinkler protection under the obstruction. What if you have multiple parallel obstructions that are less than 4 ft wide with gaps in between?
For example, multiple 36-inch diameter parallel pipes with 6 inches of space between each pipe.
I feel that even if these obstructions do not require sprinkler protection below per code, they would still significantly alter the listed spray pattern of the sprinkler. I have seen some info regarding a 50% rule, but I can only find that in code as it relates to ceiling fans.
I am curious what other opinions are. Thanks!
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