XR250
Structural
- Jan 30, 2013
- 6,059
Doing a foundation design for a un-convential 50x100 PEMB that is to be used for a Furniture Store. It has light gage frames at 5' O.C. spanning 50 ft.
The building designer is using 12 PSF for the Roof LL and 2 PSF for the DL.
Based on a 250 sq. ft. frame trib, my numbers indicate he can use 19 psf min. for a the live load.
Apparently, he is trying to use this portion of the IBC:
"In structures such as greenhouses, where special scaffolding is used as a work surface for workers and materials during maintenance and repair operations, a lower roof load than specified in the following equations shall not be used unless approved by the building official. Such structures shall be designed for a minimum roof live load of 12 psf"
He has called out the note about the scaffolding. Is there ANYWAY this can be justified for a furniture store? I believe 12 psf is above the snow load for this area, but barely (central NC). Unfortunately, I don't think he can get the building to work with any larger loads so he is grasping at straws. I have never seen ANY PEMB designed with less than 20 psf for the roof load - possibly reduced for trib area.
Also, 2 psf DL? I guess there is no allowance for any PM&E except for helium balloons.
FWIW, I was not involved in spec'ing the building, nor am I the designer of record. I doubt the building official will approve this.
The building designer is using 12 PSF for the Roof LL and 2 PSF for the DL.
Based on a 250 sq. ft. frame trib, my numbers indicate he can use 19 psf min. for a the live load.
Apparently, he is trying to use this portion of the IBC:
"In structures such as greenhouses, where special scaffolding is used as a work surface for workers and materials during maintenance and repair operations, a lower roof load than specified in the following equations shall not be used unless approved by the building official. Such structures shall be designed for a minimum roof live load of 12 psf"
He has called out the note about the scaffolding. Is there ANYWAY this can be justified for a furniture store? I believe 12 psf is above the snow load for this area, but barely (central NC). Unfortunately, I don't think he can get the building to work with any larger loads so he is grasping at straws. I have never seen ANY PEMB designed with less than 20 psf for the roof load - possibly reduced for trib area.
Also, 2 psf DL? I guess there is no allowance for any PM&E except for helium balloons.
FWIW, I was not involved in spec'ing the building, nor am I the designer of record. I doubt the building official will approve this.