Denver Colorado Roofing Codes

These are the Denver Colorado roofing codes. There are special permits required for any new roof penetration such as a skylight, swamp cooler or solar panels. The class of roof is determined by the building’s construction type.

Information Updated On

9/1/18

Building Department Phone

720-865-2520

Inspection Line

720-865-2501

Permits

Department Website

Informational Handout

Current Building Code

2015 IBC/IRC & 2016 Denver Building Code Amendments

Current Energy Code

2015 IECC

Requires a Building Permit

Yes

Other/Special Permits required

All new roof penetrations require a permit (e.g., skylight, rooftop units,

pipes, solar, etc.).

Roof System/Fire Rating required for Commercial Buildings

Class A

Special conditions

Class of roofing depends on the building’s type of construction per the IBC/IRC

Minimum sustained wind speed rating for Asphalt Shingles

Areas east of Federal Blvd. – 115 mph min. rating

Federal Blvd. to Sheridan Blvd. – 125 mph min. rating

Sheridan Blvd. to Kipling St. – 140 mph min. rating

ASTM Standard for wind rating

D-3161 and D-7158

Requires wind nailing

Per manufacturers instructions

Inspectors carry ladders for the final

Yes, with one story access.

Requires midroof (in progress) inspection

Tile roof require mid-roof inspection at 30% complete. All other materials are only required if identified in a pre-inspection.

Maximum number of layers of asphalt shingles permitted

Two layers permissible, must tear off down to deck.

Maximum number of layers of flat roof material permitted

Two layers permissible, must tear off down to deck.

Require a sheathing/decking inspection

No

Requires drip edge

Yes

Drip edge size minimum

Minimum 2” overlap for segments, extend a minimum of 1/4” below roof sheathing and a minimum of 2” onto roof deck.

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 15 pound

Underlayment required for 4:12 and above

15 pound

Type of valleys allowed

Both, no closed valleys with metal liner.

Valley Underlayment/Material required for closed valleys

Closed valleys shall be a minimum of 36” wide of either 1) one ply of smooth roll roofing or 2) self-adhering modified bitumen. Metal is not allowed in a closed valley.

Valley Underlayment/Material required for open valleys

Open valleys lined with metal shall be a minimum of 24” wide and corrosion resistant. Open valleys lined with two plies of rolled roofing shall be permitted where the bottom layer is at least 18” wide and the top layer is at least 36” wide.

Kick-out required on Step Flashing

Yes

Minimum curb height requirement

8”

Chimney crickets requirement

All vertical projections on sloped roofs greater than 30” require a cricket or saddle made of sheet metal or of the same material as the roof covering.

Requires ridge cap

Yes

Requires ventilation to meet building codes

Yes on new construction only

Requires Soffit eave/vents

Yes on new construction only

Special insulation code requirements

Per energy code

Allows 90 lb rolled roofing on low slope heating living space

Yes

Slope

2:12

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