Skyler We used to see WSRB or FM jobs with 0.39 gpm/sf over 5,600 sf as standard warehouse design. Based on previous engineers comments we normally said structural plans had to reserve 2.5 lbs/sf for sprinklers where they were deferred permit, which was always.
2.5 was conservative. Sometimes there was some concern where a designer wanted to run several 8” lines parallel to each other for a ways. The only problem that sometimes arose was attachment points and methods, and sometimes distributing the load. And convincing a spk designer that if the z-purloin engineer said 3” and larger supported every 10’, sway bracing every 20’, that No, the fire inspector and NFPA 13 were not going to overrule the Structural P.E. of Record. When designers told me to call P.E. and tell him it had to be 20’ & 40’ were they just angry they might be over their estimate, or did they really think a fire inspector just gets to make everything up? I always wondered. Best. Bruce Verhei > On June 3, 2020 at 2:15 PM Skyler Bilbo via Sprinklerforum > <[email protected]> wrote: > > The structure needs to support a larger point load (with a very complex > explanation, it probably does). Otherwise, if a guy working on the roof were > to stand on one foot, the structure could potentially collapse. Structural > engineering calculations are extremely complex (I would say more so than our > hydraulic calculations). > > The answer I can give that would be most helpful: I have had a similar > situation on a project. Because of the complexities of structural > engineering, I let the structural engineer deal with it (as they should, by > law). I sent over our drawings, showing piping layout, hanger locations, > with a table of pipe weight per foot, and section 9.1.1.2 (a), nice and big > on the drawing (five times the weight of the water-filled pipe plus 250 lbs > at each point of attachment). In the email I sent, I asked nicely how they > would like us to hang it. > > Oftentimes, the structural engineer will come right back and say it will > work. I have also had them come back and require the mains to be trapezed, > or supported by primary members (girders, not trusses). Sometimes they will > send the lovely note/detail we see on all Wal-Mart jobs about hangers being > at/near panel points of the bar joists, or send a detail describing hanger > attachments to purlins. > > > Commentary: I went to school for Structural Engineering (I don't > practice, and I'm not a Structural Engineer). For my senior design project > (about 10 years ago), I worked with a company that makes the metal connector > plates that hold together wood trusses, along with the structural design > software to design the trusses, and corresponding plate sizes. I brought up > our rule about five times the weight of the water filled pipe plus 250 lbs in > a meeting one time. The head engineer asked one of the other guys if they > designed for this. The reply was a long way of saying no, and there would be > plenty of cases where real truss designs would fail the calculations, if they > took this into account. The head engineer let out an audible "Hm", and we > moved on. In my later work with them, I learned that their designs (per ASCE > 7) have a built in safety factor, such that the trusses can typically hold 2 > to 3 times what they are designed for. This could help explain why it seems > like such a large problem in the design phase of projects, and not as much of > a problem in the real world (I imagine you could easily take down a structure > if you hang some 12" main and turn the water on, without the structure being > designed for it). > > There is a disconnect between how structures are designed and the point > load described by NFPA 13. As Ken alluded to, our seismic bracing > calculations vs. the actual structural design is probably a much larger > disconnect. I'm sure there are other people that can detail this disconnect > much better than I can (Ken), but I believe ASCE-7 takes our pipe/hangers > into account as a uniform dead load, which is usually accounted for as part > of a "miscellaneous load" or "mechanical system" dead load for all of the > mechanical systems across the entire structure, which is expressed as some > number of pounds per square foot. This 1 to 15 lbs/sq ft (or so) is usually > a safe assumption, but it can often be an issue at mains, where the loads can > be higher than what they have accounted for. I have also seen this being a > larger load than the structural engineer expected (and designed for) in tall > warehouses, where lines are 2-1/2" or 3". Long story short: from what little > I know, structures are not designed the way most of us in the sprinkler world > probably think they are. And somehow, this probably isn't an issue over > 99.9% of the time. > > > Again, this is complex, and not our job, so send it to the structural > engineer, and let them deal with it. Just like my last post about asking the > Architect to do their job. Now, if we could just get the other trades to > install everything per plans (and/or Construction Management companies that > actually coordinate things), life would be so much easier for all of us. > > > Good luck, > Skyler Bilbo > > Wente Plumbing and FIre Protection > 1700 S. Raney Street > Effingham, IL 62401 > 217-819-6404 Direct > 217-347-7315 Fax > > [email protected] > mailto:[email protected]://www.wenteplumbing.com > > **new**http://www.beplumb.com > Like us on facebook http://www.facebook.com/justbeplumb for updates > > > On Wed, Jun 3, 2020 at 11:41 AM Ron Greenman via Sprinklerforum < > [email protected] > mailto:[email protected] > wrote: > > > > And remember the building does not belong to you and it > is NOT your responsibility to come up with a solution. The owner, via his > representatives (the GC, the structural engineer, and ultimately, the > architect) is responsible for building a code-compliant building that > includes supporting any live or dead loads, including the sprinkler system. > And I'm guessing that in California insufficient point loading for hanging > would the least of your concerns regarding structure. > > > > > > > > Ron Greenman > > > > [email protected] mailto:[email protected] > > > > 253.576.9700 > > > > The Universe is monstrously indifferent to the presence of man. > > -Werner Herzog, screenwriter, film director, author, actor and opera > > director (1942-) > > > > > > On Wed, Jun 3, 2020 at 9:26 AM John Denhardt via Sprinklerforum < > > [email protected] > > mailto:[email protected] > wrote: > > > > > > > I agree with Ken. I have been down this road > > before. The structure needs to support the piping plus 250 pounds at the > > point of hanging. If the structure can handle this load, then the > > structure has an issue. > > > > > > Thanks, > > > John > > > > > > John August Denhardt, PE > > > Vice President, Engineering and Technical Services > > > American Fire Sprinkler Association > > > m: p: 301-343-1457 > > > 214-349-5965 ext 121 > > > w: http://firesprinkler.org > > > https://www.facebook.com/firesprinkler.org/ > > > https://twitter.com/afsa/status/1039528345367732224 > > > https://www.linkedin.com/company/american-fire-sprinkler-association-afsa-/ > > > https://www.instagram.com/firesprinklerorg/ > > > > > > > > > Help AFSA “Sound the Alarm” about sprinklers! > > > > > > AFSA’s charitable partner the American Red Cross is educating > > > millions through its Home Fire Preparedness Campaign. Help us support the > > > inclusion of fire sprinklers in their messaging. Donate today! > > > https://www.redcross.org/donate/cm/afsa-pub.html/ > > > > > > > > > > > > On Wed, Jun 3, 2020 at 12:18 PM Parsley Consulting via > > > Sprinklerforum < [email protected] > > > mailto:[email protected] > wrote: > > > > > > > > > > Jerry, > > > > > > > > Although I'm slightly unclear over what you're being > > > > told I would make sure that whoever is providing that information to > > > > you has read 9.2.1.3.1 of the '16 edition of -13: > > > > > > > > > > > > > 9.2.1.3.1 Sprinkler piping shall be > > > > substantially supported from the building structure, which must support > > > > the added load of the water-filled pipe plus a minimum of 250 lb (115 > > > > kg) applied at the point of hanging, except where permitted by > > > > 9.2.1.1.2, 9.2.1.3.3, and 9.2.1.4.1 > > > > > > > > > > > > > > 9.2.1.1.2 deals with toggle hangers > > > > > supporting pipe 1½" and smaller, 9.2.1.3.3 covers flexible hose > > > > > fittings, and 9.2.1.4.1 covers branch hangers into a metal deck. > > > > > > > > It's pretty clear that the structure has to be able to > > > > support at least the load noted in 9.2.1.3.1. > > > > > > > > As I am a principal member of the hanging and bracing > > > > committee, please see the disclaimer below. > > > > > > > > sincerely, > > > > Ken Wagoner, SET > > > > Parsley Consulting > > > > 350 West 9th Avenue, Suite 206 > > > > Escondido, California 92025 > > > > Phone 760-745-6181 > > > > Visit the website http://www.parsleyconsulting.com/ > > > > > > > > IMPORTANT NOTICE: This correspondence is not a Formal > > > > Interpretation issued pursuant to NFPA Regulations. Any opinion > > > > expressed is the personal opinion of the author and does not > > > > necessarily represent the official position of the NFPA or its > > > > Technical Committees. In addition, this correspondence is neither > > > > intended, nor should it be relied upon, to provide professional > > > > consultation or services > > > > > > > > It should be noted that the above is my opinion as a > > > > member of the NFPA Automatic Sprinkler System Hanging and Bracing > > > > Committee in accordance with the NFPA Regulations Governing Committee > > > > Projects and should therefore not be considered, nor relied upon, as > > > > the official position of the NFPA or its Committees > > > > > > > > > > > > On 06/03/2020 8:25 AM, Jerry Van Kolken via > > > > Sprinklerforum wrote: > > > > > > > > > > > > > > > > > > I have a building where they are telling me the > > > > > structural point loading on the framing less than 250lbs. (140lbs) > > > > > > > > > > > > > > > > > > > > Advice? > > > > > > > > > > > > > > > > > > > > Jerry Van Kolken > > > > > > > > > > Millennium Fire Protection Corp. > > > > > > > > > > 2950 San Luis Rey Rd. > > > > > > > > > > Oceanside, CA 92058 > > > > > > > > > > (760) 722-2722 FX 722-2730 > > > > > > > > > > > > > > > > > > > > > > > > > _______________________________________________ > > > > > Sprinklerforum mailing list > > > > > [email protected] > > > > > mailto:[email protected] > > > > > > > > > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > > > > > > > > > > > > > > > > > > > _______________________________________________ > > > > Sprinklerforum mailing list > > > > [email protected] > > > > mailto:[email protected] > > > > > > > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > > > > > > > > > > > > > > > _______________________________________________ > > > Sprinklerforum mailing list > > > [email protected] > > > mailto:[email protected] > > > > > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > > > > > > > > _______________________________________________ > > Sprinklerforum mailing list > > [email protected] > > mailto:[email protected] > > > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > > > > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org >
_______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
