I certainly agree that a skylight is a type of ceiling pocket but when you use them interchangeably, it's a problem. There are significant differences in the criteria (most notable being no height limits nor material restriction for the covers in skylights). Like apples and oranges are both fruits but if you're making a pie, I wouldn't use them together.
The 2010 ed. also made some significant changes. sprinklers in the lower ceiling elevation when the higher ceiling elevation is within 12 in. of the deflectors or greater for sprinklers with greater listed distances from the higher ceiling should not be considered unprotected ceiling pockets. A.8.6.7.2(4) It is the intent of this section to allow compartments with multiple pockets, where the cumulative volume of the pockets exceeds 1000 ft3 and separated from each other by 10 ft or more and still be permitted to be unprotected because with these values, a sprinkler would be required between such pockets. For smaller pockets where the cumulative volume does not exceed 1000 ft3, there is no reason to separate the pockets by any specific distance because they are not worse than a single pocket that is 1000 ft3. Roland On Sep 22, 2009, at 6:04 PM, Frans Stoop wrote: > Roland, > > Thanks for your guidance. > However, with all respect, I disagree about the mix-up. > According to 8.5.7 a sky light is a ceiling pocket, considering the > wording "sky lights and similar ceiling pockets". > (A sky light is a ceiling pocket, but not every ceiling pocket is a > sky light.) > > This is how I see it: > In the case of the hall in concern we have Standard Upright Spray > Sprinklers (chapter 8.6) and sky lights (= ceiling pockets) less than > 914 mm deep. > Ergo: section 8.6.7 applies and if the 7 conditions are met par. > 8.6.7.2 applies too. > All sprinklers in the hall are QR sprinklers. The sky lights are less > than 914 mm deep. > Each sky light is less than 4.5 m3. Every 5 or 6 sky lights make up a > cluster. Spacing between the sky lights within a cluster is approx. 1 > m. Each cluster is less than 28.3 m3. Spacing between clusters is > more than 3.05 m. > The covers are all safety glass. > > Your comparison of a smoke/heat vent with a plastic cover was > enlightening for me. > Indeed, size matters. > > Frans Stoop _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
