These are the specs for the City of Centennial Colorado roofing codes. Note there is a requirement for midroof inspections, and there is a minimum asphalt saturated underlayment requirement.

Information Updated On

8/22/18

Building Department Phone

303-754-3321

Inspection Line

303-754-3321

Fax Line

303-708-1790

Department Website

Informational Handout

Current Building Code

2015 IRC/IBC

Current Energy Code

2015 IECC

Requires a Building Permit

Yes

Roof System/Fire Rating required for Residential Dwellings

Class A

Minimum sustained wind speed rating for Asphalt Shingles

90 MPH Sustained/110 MPH 3-second gusts

Requires wind nailing

Yes

Inspectors carry ladders for the final

Yes, with one story access

Requires midroof (in progress) inspection

Yes, inspection required at 25% to 75% shingled for concrete, tile, and shake shingle, metal, and flat roofs.

Maximum number of layers of asphalt shingles permitted

Single layer only

Maximum number of layers of flat roof material permitted

Single layer only

Require a sheathing/decking inspection

No

Requires solid sheeting (plywood/OSB) over spaced decking

Yes

Minimum gap size for sheeting

½ inch gap

Requires drip edge

No

Requires Rake/Gable metal edging

No

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

No

Underlayment required 2:12 up to 4:12

Minimum 15-pound asphalt saturated underlayment required. 19-inch laps of underlayment are required, starting with a 19-inch strip and then full sheets.

Underlayment required for 4:12 and above

One layer of 15-pound (minimum) asphalt saturated underlayment required.

Type of valleys allowed

Both

Valley Underlayment/Material required for closed valleys

90 pound

Valley Underlayment/Material required for open valleys

Ice and water under metal

Kick-out required on Step Flashing

Yes

Minimum curb height requirement

No

Chimney crickets requirement

30 inch or greater width

Requires ridge cap

Yes

Requires ventilation to meet building codes

Yes

Requires blower door test when increasing ventilation to code

No

Requires Soffit eave/vents

No

Allows 90 lb rolled roofing on low slope heating living space

Yes

Slope

2:12