I am working on a location where two 7" diameter roof drains have been installed in the proximity of some sidewall sprinklers. They create obstructions and my job is to figure out solutions. Some are clearly a problem, but others are in the gray zone. A couple of questions:
1) In some of the areas, the drain pipes run tight to the wall with the center line of the top one approximately 12" below the sprinkler and the lower one 15" c/l below that. Given that the top pipe is 9" from the deck and there is only a 3" gap between the two pipes, could this be considered a de facto soffit? If so, then 8.7.4.1.3 would be applicable and the sidewall sprinkler could be extended up to 8" out without a sprinkler below. 2) At some point, the drain pipes turn 90 degrees and run out from the wall. They are not tight to the ceiling, but do present a possible obstruction. Section 8.7.5.1.4 describes criteria for this, but figure 8.7.5.1.4 shows an obstruction that is tight to the ceiling and dictates distance for discharge underneath. Section 8.7.5.2.2 discusses sprinkler discharge over suspended or floor mounted obstructions. In this situation, I have the potential for discharge both over and under, do I have to make both apply, if that is even possible? BTW, the text of section 8.7.5.1.4 describes rules for objects projecting from the same wall. Figure 8.7.5.1.4 diagrams the situation with the obstruction tight to the ceiling, but the text does not specify that the obstruction be tight. Likewise, section 8.7.5.2.2 discusses sprinkler discharge over suspended or floor mounted obstructions. That text does not specify what orientation the obstruction is in, but figure 8.7.5.2.2 shows it perpendicular to the throw. Both the text and diagram are part of the Standard. If the diagram shows something that is more restrictive than the text, does that imply that the diagram is the Standard, since the more restrictive applies when there is a conflict? Or does the text take precedence over the diagram? Welcome to my Monday Todd G. Williams, PE Fire Protection Design/Consulting Stonington, Connecticut www.fpdc.com 860.535.2080 _______________________________________________ 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)
