Here is a listing of the Commerce City Colorado roofing codes. Note the current energy code is based on 2009 requirements.

Information Updated On

9/16/2018

Building Department Phone

303-289-3683

Inspection Line

303-289-3652

Permits

Fax

Department Website

Current Building Code

2009 IBC/IRC

Current Energy Code

2009 IECC

Requires a Building Permit

Yes

Other/Special Permits required

A roofing/re-roofing permit is only for roof new covering installations and/or replacement of existing roof coverings. Sheathing/decking replacement is allowed with roofing or re-roofing permit provided it is included in the description of work. Any other work (e.g. structural modifications) requires a separate permit.

Roof System/Fire Rating required for Residential Dwellings

Class C

Special conditions

Class C allowed on one and two-family dwellings. Other roof covering classifications vary based on the type of construction as defined in the 2009 IBC

Minimum sustained wind speed rating for Asphalt Shingles

90 MPH or 3 second gust

Other wind speed rating

Exposure category C unless engineering analysis justifies different exposure category

Requires a manufacturer’s wind warranty

No

Requires wind nailing

No

Inspectors carry ladders for the final

Yes, but only with one story access. 

Requires midroof (in progress) inspection

Yes, required at 50% complete.

Maximum number of layers of asphalt shingles permitted

Two layers

Maximum number of layers of flat roof material permitted

Two layers

Require a sheathing/decking inspection

Yes

Requires solid sheeting (plywood/OSB) over spaced decking

Yes

Minimum gap size for sheeting

3/8” gap

Requires drip edge

Yes

Drip edge size minimum

1 x 2

Requires Rake/Gable metal edging

Yes

Enforces the use of Self Adhering Underlayment (i.e., Ice & Water)

No

Underlayment required 2:12 up to 4:12

19” overlap of 30 pound

Underlayment required for 4:12 and above

15 pound 

Type of valleys allowed

Open and closed

Valley Underlayment/Material required for closed valleys

90 pound

Valley Underlayment/Material required for open valleys

90 pound under metal

Kick-out required on Step Flashing

Yes

Minimum curb height requirement

None

Chimney crickets requirement

Yes

Requires ventilation to meet building codes

Yes, attic ventilation must be brought up to current code on tear offs to deck.

Requires Soffit eave/vents

No