Climate Design Criteria

All new construction placed in unincorporated Gunnison County shall be constructed so as to meet the snow load requirements at the proposed building site. The value of ground snow loads at building sites shall be determined through

"2016 Colorado Design Snow loads," prepared by the "Structural Engineers Association of Colorado Snow Load Committee."

The report can be found on Sea Colorado. This report provides the recommended design ground snow loads which are intended to be used with ASCE 7 procedures for structural design. Once the ground snow load at the building site is determined, it must then be converted to roof snow loads according to ASCE 7, with appropriate treatment of exposure to wind, thermal properties of the roof, roof slope, unbalanced snow loads, drifting, and risk exposure.

Table R301.2(1) Climatic and Geographic Design Criteria

Ground Snow Load:

Varies. The value of roof (or other member) snow load shall be equal to the "recommended basic snow load" as defined in the "2016 Colorado Design Snow Load," prepared by the "Structural Engineers Association of Colorado," ASCE 7 procedures shall be used to convert to roof snow loads.

Wind Design:

Speed (miles per hour): 104, 3-second gust for exposure C.

Topographic effects: no
Special wind region: no
Wind-borne debris zone: no

Seismic Design Category:

C for the site soil classification D

Subject to Damage from:

Weathering: severe
Frost line depth: 36 inches
Termite: slight

Ice Barrier Underlayment Required:

Flood Hazard:

1989, Resolution 89-31, 2013 FIRM maps

Air Freezing Index:

3447 (BF-days-100 year)

Manual J Design Criteria:

Elevation feet: 7,674 at Automated Weather Observing System

Altitude correction factor: 0.75
Latitude degrees north: 39
Coincident wet bulb: 52
Indoor winter design dry-bulb temperature: 70
Outdoor winter design dry-bulb temperature: -22
Heating temperature difference: 92