Struct-007
Structural
- Aug 7, 2020
- 32
ASCE7-16, Equation 4.8-1: (Lr = Lo R1 R2) where 12 ≤ Lr ≤ 20
Does 12 ≤ Lr ≤ 20 imply that Equation 4.8-1 is applicable only when the roof live load from table 4.3-1 is taken as 20 psf?
And in Section 4.8.2, there is this statement: "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 Eq. (4.8-1) shall not be used unless approved by the Authority Having Jurisdiction (AHJ). On such structures, the minimum roof live load shall be 12 psf (0.58 kN∕m2)."
This confused me a bit. Does it imply that a lower roof load than specified in Eq. 4.8-1 can be used without the approval of AHJ if no special scaffolding is used? And does the 12 psf lower limit only apply where special scaffolding is used?
Does 12 ≤ Lr ≤ 20 imply that Equation 4.8-1 is applicable only when the roof live load from table 4.3-1 is taken as 20 psf?
And in Section 4.8.2, there is this statement: "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 Eq. (4.8-1) shall not be used unless approved by the Authority Having Jurisdiction (AHJ). On such structures, the minimum roof live load shall be 12 psf (0.58 kN∕m2)."
This confused me a bit. Does it imply that a lower roof load than specified in Eq. 4.8-1 can be used without the approval of AHJ if no special scaffolding is used? And does the 12 psf lower limit only apply where special scaffolding is used?
