Calculators / Snow Loads

Snow Loads

ASCE Hazard Tool Code edition

Ground Snow,

p_g

ASCE 7-22: Figure 7.2-1

Risk Category

ASCE 7-22: Table 1.5-1

Winter Wind Parameter,

W_2

ASCE 7-22: Figure 7.6-1

Snow Region 1

Region Description

Roof R-value (h·ft²·°F/Btu)

ASCE 7-22: §7.3.2

Balanced Flat Roof Snow Load

p_f = 0.7 C_e C_t p_g

(ASCE 7-22: Eq. 7.3-1)

Exposure Factor,

C_e

ASCE 7-22: Table 7.3-1

Thermal Condition

ASCE 7-22: §7.3.2

Thermal Factor,

C_t

ASCE 7-22: Table 7.3-3

Ground Snow Load Factor,

p_g

ASCE 7-22: Figure 7.2-1

Balanced Flat Roof Load,

p_f

Balanced Sloped Roof Snow Load

p_s = C_s p_f

(ASCE 7-22: Eq. 7.4-1)

Roof Obstructions/Friction

User Defined

Roof Slope,

\theta

User Defined

Thermal Factor,

C_t

ASCE 7-22: Table 7.3-3

Slope Factor,

C_s

ASCE 7-22: §7.4.1

Balanced Sloped Roof Load,

p_s

Minimum Snow Load

p_m

(ASCE 7-22: §7.3.4)

Minimum Roof Snow Load,

p_m

ASCE 7-22: §7.3.4

Governing Balanced Snow Load

Maximum of balanced and minimum loads

Drift Loads for Roof Projections and Parapets

p_d = \gamma h_d

(ASCE 7-22: §7.8)

Location	Upwind Fetch, $l_u$ (ft)	Parapet Height, $h_{pt}$ (ft)	Action

Location	Balanced Height, $h_b$	Clear Height, $h_c$	Drift Height, $h_d$	Drift Load, $p_d$	Drift Width, $w$	Total, $p_{total}$
Parapet 1	1.16 ft	2.34 ft	2.34 ft	41.9 psf	18.7 ft	62.6 psf

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