ZIP Code 60474
Grundy County, Illinois — South Wilmington
What This Means
Grundy County, Illinois has a light ground snow load of 20 PSF per ASCE 7-22. At this level, most standard residential roofs are designed to handle the load without issue. However, flat or low-slope roofs should still be checked for drifting and sliding snow.
Snow Load Details
| ZIP Code | 60474 |
| County | Grundy |
| City | South Wilmington |
| State | Illinois (IL) |
| Ground Snow Load | 20 PSF — Light |
| Classification Range | 1 - 20 PSF |
| Data Quality | Measured |
Source: ASCE 7-22 ground snow load polygons via ArcGIS
Roof Snow Load Calculator
ASCE 7-22 flat roof formula: pf = 0.7 × Ce × Ct × Is × pg
Your ground snow load (pg): 20 PSF
ⓘ Simplified estimate for flat roofs. Sloped roofs, drift zones, and unbalanced loads need additional calculations. Consult a structural engineer for final design.
Grundy County Snow Load Map
Counties colored by snow load classification. Gray = No Load, Blue = Light, Amber = Moderate, Orange = Heavy, Red = Extreme, Purple = Case Study.
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Frequently Asked Questions
What is the ground snow load for ZIP code 60474?
ZIP code 60474 is in Grundy County, Illinois, with a ground snow load of 20 PSF, classified as light per ASCE 7-22.
Is my roof strong enough for snow in 60474?
With a light ground snow load of 20 PSF, standard residential construction typically handles this load, but verify with your local building code.
What county is ZIP code 60474 in?
ZIP code 60474 is in Grundy County, Illinois (IL).