Uhhhhh, no.   Heat shoots right past the sprinkler an collects at the top; 
depending on the size of the well, it will log down to the sprinkler at some 
point, but unless you do a fire model that can reasonably predict response 
time, it's not a conforming condition.  I cannot say how many times I've seen a 
sprinkler 3', 4' and more below the lens of a skylight. That the GC produced an 
approved plan from another jurisdiction is actually pretty funny and I wonder 
if they have a bag of tricks where the can pull out "evidence" of acceptability 
for other errors, omissions and discrepancies.   "Look, we did this in 2003 in 
Dry Gulch County, why can't we do it here?"

Several years ago, I got a plan review correction (I can't even remember what 
it was now) from City of SD that was based on an NFPA 13 requirement to include 
something in the plans that we never had done as a regular practice in this 
city.  And it was an inconvenience at the time - it was probably to put the 
restrictor settings for every PRV hose and control valve on the plans for a 
high-rise, or calculate every seismic brace instead of the lazy man's 
worst-case scenario approach that only entailed doing a single detail for all 
the lats and longs on the system.   Anyway, our plan review section at the time 
wasn't known for its strident enforcement of every nuance in the standard, so I 
asked the section supervisor why they were requiring it because, "...we've 
never been asked to do that before."   And his answer was a gem, "Just because 
we've been doing it wrong all this time doesn't mean that we should keep doing 
it wrong."  So that "other" jurisdictional approval means nothing except that 
the engineer who stamped the plan and AHJ that approved it don't know the 
standard.

In terms of advice for Todd, I would pull out the book and try to teach them 
that such a large skylight is a feature that warrants its own complement of 
sprinklers, spaced to the extents of the well, from headwall to headwall both 
ways, and that sprinklers must be positioned per the deflector distance 
provisions of whatever type of sprinkler you're using.   It's pretty clear in 
the standard, methinks.


Steve L.


From: daren welborn <[email protected]>
Sent: Friday, February 13, 2026 7:02 AM
To: Sprinklerforum <[email protected]>
Subject: [Sprinklerforum] Re: Sprinklers in skylights.

I would assume the theory is that the smoke plume or heat would riser along the 
edge of the opening up to the skylight, therefore setting off the sidewall 
sprinklers???
________________________________
From: Fpdcdesign <[email protected]<mailto:[email protected]>>
Sent: Friday, February 13, 2026 9:04 AM
To: Sprinklerforum 
<[email protected]<mailto:[email protected]>>
Subject: [Sprinklerforum] Sprinklers in skylights.

I am fighting, yet again, old sprinkler in the skylight battle. The skylight is 
about 60 ft long, 12 ft wide and 4.5 ft from the bottom of the skylight opening 
to the peak.

I showed a single line at the peak with uprights. Obviously to GC doesn't like 
that. They have a plan from a building in another state with sidewalls in a 
soffit several feet down from the peak. This was stamped, approved and 
installed.

Is there any justification (Code, fire test, etc) for the sidewall arrangement? 
 If not, why is this still getting approved? This has been going on for a long 
time.

Todd Williams
Fire Protection Design/Consulting
Stonington, CT
860-608-4559
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