Suspended Walkable Ceiling Live Load
Suspended Walkable Ceiling Live Load
(OP)
Designing a cold production and storage facility.
The Production Room inside the facility is to have a walkable insulated ceiling, suspended and supported by the roof Open Web Steel Joist (OWSJ) bottom chords.
One supplier said the live load could be 20 PSF. When i asked where he got that load information from, he said the code book. I don't see this anywhere in IBC.
One manufacturer said 30 PSF.
I intended to use 40 PSF for catwalks, per code, but, then the supplier stated that would be MUCH more expensive.
(For IBC 2009 Live Load Table 1607.1, please see attached...)
https://res.cloudinary.com/engineering-com/image/upload/v1481044100/tips/LL2009_uvnije.pdf
In IBC 2009, what exactly does "Primary roof members, exposed to a work floor" mean? This walkable ceiling is intended for equipment maintenance, thus, could be construed as a "work floor". Could i justify this 20 PSF for a walkable ceiling?
Any suggestions on how i could justify 20 psf? Other suggestions?
Thank you!
The Production Room inside the facility is to have a walkable insulated ceiling, suspended and supported by the roof Open Web Steel Joist (OWSJ) bottom chords.
One supplier said the live load could be 20 PSF. When i asked where he got that load information from, he said the code book. I don't see this anywhere in IBC.
One manufacturer said 30 PSF.
I intended to use 40 PSF for catwalks, per code, but, then the supplier stated that would be MUCH more expensive.
(For IBC 2009 Live Load Table 1607.1, please see attached...)
https://res.cloudinary.com/engineering-com/image/upload/v1481044100/tips/LL2009_uvnije.pdf
In IBC 2009, what exactly does "Primary roof members, exposed to a work floor" mean? This walkable ceiling is intended for equipment maintenance, thus, could be construed as a "work floor". Could i justify this 20 PSF for a walkable ceiling?
Any suggestions on how i could justify 20 psf? Other suggestions?
Thank you!






RE: Suspended Walkable Ceiling Live Load
RE: Suspended Walkable Ceiling Live Load
I didn't notice the "accessible ceilings". I'll make sure i specify that point load on the framing plan. But, in addition, and primarily, I'm looking for a justifiable Live Load pressure.
RE: Suspended Walkable Ceiling Live Load
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Suspended Walkable Ceiling Live Load
RE: Suspended Walkable Ceiling Live Load
The insulated panel, walkable ceiling, will be used for an equipment maintenance access surface above a "clean room" for cold food production.
The ceiling will be accessible by a separate catwalk.
Does that help?
RE: Suspended Walkable Ceiling Live Load
At this point, I primarily need a code justifiable reference for using a preferable 20 psf pressure.
RE: Suspended Walkable Ceiling Live Load
RE: Suspended Walkable Ceiling Live Load
RE: Suspended Walkable Ceiling Live Load
To avoid confusion, the walkable ceiling WILL cover the entire 120' x 120' Production Room. The client wants the ceiling to serve both as ceiling and maintenance access.
A separate catwalk will provide access to the walkable ceiling. For the catwalk, i WILL use 40 PSF.
I would be more than happy to specify a 40 PSF Live Load for the entire ceiling... BUT... when both the end client and the general contractor (my direct client) both have access to all Ceiling Panel Data and Spec sheets, they will demand an answer as to why i am specifying 40 PSF when the suppliers and manufacturers recommend the "typical" and historical 20 PSF. As structSU10 implied, the 40 PSF will result in considerably more support members, installation labor and cost.
Can anyone provide a code justifiable reference for specifying a 20 PSF Live load?
structSU10... when you used or specified the "Tuff-T" system, what Live Load did you specify? And what code did you reference?
RE: Suspended Walkable Ceiling Live Load
1) 20 PSF and 200 lb and;
2) A look at how many workman might aggregate over each element based on that elements tributary with.
Frankly, I'd put more stock in #2 than anything else.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Suspended Walkable Ceiling Live Load
ETA: Sorry - should have looked at the attachment before I posted. I'd probably say 300# and 20 psf is adequate for the usage provided the joists aren't exposed to below and the 2000# load in that table is indicated.
RE: Suspended Walkable Ceiling Live Load
As you've found in the code, I believe that this is above and beyond what's required and will utilize the single 200lb point load if we're doing a retrofit of an existing building.
RE: Suspended Walkable Ceiling Live Load
Thank you!
RE: Suspended Walkable Ceiling Live Load
RE: Suspended Walkable Ceiling Live Load
The reason i tend to dig so deep and consider nearly every aspect is because, on a regular basis, i deal with very competent state plan reviewers and many competent members of the general contractor team.
RE: Suspended Walkable Ceiling Live Load
RE: Suspended Walkable Ceiling Live Load
RE: Suspended Walkable Ceiling Live Load