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Live load question 1

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JoeBaseplate

Structural
Joined
May 31, 2011
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I have an interior “roof” over a door entry. No one would have access to the area, and like I said its interior. The only load is plywood and some gravel the architects want to place. I started with 20 psf live but since the stud span below is long (20’), I have to sharpen the pencil. I am not sure if there is anything in IBC06, so I am just going to design for 10 psf live. Would that be a OK?
 
It is like an attic I would guess....10 psf would make sense as long as it is not accessible....where someone might store boxes of stuff up there.

 
Wood or Steel studs? If wood, did you try LVLs in that area? Steel: Double up the studs?

There are days when I wake up feeling like the dumbest man on the planet, then there are days when I confirm it.
 
ASCE requires the following (See Table 4-1)
Uninhabitable attics w/o storage = 10 psf
Uninhabitable attics w/ storage = 20 psf


 
nuche, 8' long steel studs but they are framing on one side into the wall but on the other side they will be framing into a light gage box beam (spanning 20' with 4' trib). The box beam is where I have issues, since it will also be a headed for an interior door, I want to design it for deflection less then 1/2".
 
Slickdeals, thanks. This is though for an entry to a college lecture hall.
 
Better make it 100 psf for all the garbage that will be tossed up there prior to entering the hall.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
 
I'd probably like to put a 250lb point load, non-concurrent with the live load, on the ceiling framing to make sure a serviceman could access this area if necessary. Also I do the occasional attic inspection and that is about what I weigh :)
 
If you go with 10 psf, consider posting a sign on the top surface that defines the load rating. On something similar, we included tie-backs for fall protection during cleaning. I think the tie-backs may have been a clients request (or their insurer) rather than any code requirement.
 
I've been to college- when you are dealing with 18-21 year old kids, there is no such thing as "not accessible" . Unless it is walled in I would use 20 psf without hesitation.

What dead load are you using- and do you have any depth restrictions?
 
Just stick w/ ASCE or IBC or non-storage attics but make sure it can handle a 250# service point load.
 
Yeah I designed for 20 psf and asked the arch to get rid of the gravel on top to reduce load. The idea behind gravel was that, with that, people are less likely to walk on the surface. Not sure if I agree with that either.

As for DL, I was using 20 (12 gravel, 2.5 plywood, 2.75 gym ceiling, 1.5 MEP) but now I am just using 10 psf with 20 live.
 
Or maybe too the itinerant VW bug on the rooftop...

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
 
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