Yes and no Chris. For calcs we supply point loads and we should design to the point load strength of the structure so that hangers may need to be very close together relative to maximum. In seismic these truss systems typically require a brace on every third member. I can do this if I'm supplied with the numbers. The problem I'm railing against, and I may be at an extreme of my sensibility pendulum, is the AHJs requiring us to supply this info at a cost to us. We're a couple of sheets in a larger package and often the fire plan reviewer, particularly when a hired gun, only has our sheets and then demands that we provide info that may or may not be in the full submittal but is beyond our scope. Next you go to the GC (we're always too late in the game for my taste) and ask for info to comply with the AHJ and the GC tells us we have to do it. So pretty soon everybody, including the owner because it's obviously in his interest to not have to pay for it, is saying the requirement that the building hold up the pipe is in our book so our problem, and so the owner reaps a windfall profit on our backs. Same concept applies to the ceiling. Now some well placed verbiage in the contract specifically omitting the structural guys stuff from our scope is the best plan.
On Thu, Jul 22, 2010 at 5:59 AM, Chris Cahill <[email protected]> wrote: > I agree with much of what you say Ron. But the AHJ has a point and an "if" > on the plan IMHO doesn't make it approvable. No offense to George but the > plan ain't done if he doesn't know how the ceiling is being seismically > treated. The AHJ is just asking for which solution is being supplied. If > return bends there could be hydraulic concerns over short drops and large > plates. > > Is this really different than indentifying the structural elements on the > sprinkler plan? We certainly don't design the structure but we certainly > relay the information so the AHJ can agree we complied with spacing, > deflector height and obstructions. And occasionally it's justified to > supply calculations showing the building will hold the sprinkler pipe. We > don't do the calc's but they belong in our sprinkler package in these cases. > > Copy and paste the answers from the arch or ceiling guy, modify your plan as > necessary and you are done. > > Chris Cahill > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Ron Greenman > Sent: Wednesday, July 21, 2010 8:55 PM > To: [email protected] > Subject: Re: ASCE 7-05 > > George, > > Providing the information about the ceiling IS outside of your scope. > You only have to comply with the rules dependent on the ceiling > arrangement. Submittal drawings need only carry a note that to the > effect that if the ceiling is not seismically qualified then you will > comply with one of the two methods allowed per 13. Or just put the big > plate option on then tell the architect that that is what you intend > to do because you don't know about the seismic qualities of the > ceiling. I'll bet it takes no more than a couple of hours to get the > info of what the CEILING GUY intends to do and I'll bet he will intend > to brace the grid. This getting us to do all this leg work like making > sure the building will hold up the pipes is one of my pet peeves. > HELLO!!!! It's not my building. I don't have to put the pipes in, the > owner does. He just hired me to do it 'cause he can't/he's lazy/he's > got other stuff to do/etc. The pipes weigh what they weigh. I'll tell > him how much and I'll even tell him what the point loads will be and > find what I consider the best points of attachment to be. That's my > job. Whether the building is strong enough to deal with those forces > is his and his BUILDING DESIGNER's problem. I'm happy to coordinate > but it's HIS building. Same applies to the ceiling. I have enough of a > problem hitting center tile per the plans and then getting on site to > find that the layout has been turned 90 degrees or started from the > opposite end than was on that plan. As to what's meant by head > extension I've always read that to mean "drop" and not a "head > extender" per se. > > On Wed, Jul 21, 2010 at 12:57 PM, George Medina Jr <[email protected]> wrote: >> >> I have a plan checker requiring me to call out the required T-bar ceiling > grid construction in accordance with ASCE- 7-05 (Sec. 13.5.6.2.2 - 13.6.8.4) > I do not have sections 13.3.1. & 13.3.2 which are referenced in the > aforementioned sections. Does anyone have code sections 13.3.1 & 13.3.2? The > fire sprinkler plan checker had sent me copies from there FPE who happens to > be on vacation for 2 weeks. >> I believe the t-bar ceiling call out is outside my scope of work, but upon > further reading There is a requirement for Fire Sprinkle Piping for being in > Seismic Zone 4. Section 13.5.6.2.2 (e.) >> States: >> "Except where rigid braces are used to limit lateral deflections, > sprinkler heads and other penetrations shall have a 2" oversize ring, > sleeve, or adapter through the ceiling tile to allow for free movement of at > least 1 in. in all horizontal directions. Alternatively, a swing joint that > can accommodate 1 in. of ceiling movement in all horizontal directions is > permitted to be provided at the top of the sprinkler head extension" Does > head extension imply drop? >> >> How would I determine the Design Strength of Sections 13.6.8.3 - 3 > (a.),(b.) & (c.)? >> >> I am not Familiar with these code sections, and if there is anyone with > experience in it, your guidance would greatly be appreciated. >> >> George Medina Jr. >> >> = >> _______________________________________________ >> 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) >> > > > > -- > Ron Greenman > Instructor > Fire Protection Engineering > Bates Technical College > Tacoma, WA > > Member: > AFT WA 4184/AFL-CIO, SFPE, ASCET, NFPA, AFSA, NFSA AFAA, NIBS, WSAFM, WFC > _______________________________________________ > 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) > > _______________________________________________ > 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) > -- Ron Greenman Instructor Fire Protection Engineering Bates Technical College Tacoma, WA Member: AFT WA 4184/AFL-CIO, SFPE, ASCET, NFPA, AFSA, NFSA AFAA, NIBS, WSAFM, WFC _______________________________________________ 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)
