Colorado Wildfire Resiliency Code siding requirements

Refer to the State Website to determine the Fire Intensity Classification. Click on the map link on the State website and find the property in question.

Replacement of siding requires a building permit.

In Low and Medium/High Classifications and replacing more than 25% of the siding, all the siding will be required to comply with the Colorado Wildfire Resiliency Code and the 5’ of Home Ignition Zone (defensible space) is required.

There are basically 3 classifications, No Hazard, Low Hazard and Medium/High Hazard.

No Hazard has no Wildfire requirements. It is recommended but not required.

Low and Medium/High Hazard

• Eaves and soffits must be protected on the underside by noncombustible, ignition-resistant, or 1-hour fire-resistance-rated materials.
• Exterior walls must meet specific fire-resistance ratings or be constructed of approved noncombustible, heavy timber, fire-retardant treated wood, or ignition-resistant materials.
• Exterior wall coverings are limited to noncombustible, fire-retardant treated wood, or ignition-resistant materials (vinyl siding is allowed only if the underlying wall assembly meets specific fire-resistance ratings).

Please provide the manufacturer’s information for the proposed siding and clearly show that the siding meets the criteria defined in the Wildfire Resiliency code.

Ignition-resistant building material. A type of building material that resists ignition or sustained flaming combustion sufficiently so as to reduce losses from wildfire exposure of burning embers and small flames.

Noncombustible

As applied to building construction material means a material that, in
the form in which it is used, is either one of the following:
1. Material of which no part will ignite and burn when subjected to fire.
2. Any material conforming to ASTM E136 shall be considered noncombustible within the meaning of this section.
3. For the purposes of this code, fire-rated gypsum board tested in accordance with ASTM C1396 with no less than a 1-hour fire-resistance-rating with fire exposure from the outside only is considered a noncombustible material.

Fire-retardant-treated wood

Fire-retardant-treated wood is any wood product that, when impregnated with chemicals by a pressure process or other means during manufacture, shall have, when tested in accordance with ASTM E84 or UL 723, a listed flame spread index of 25 or less. The ASTM E84 or UL723 test shall be continued for an additional 20-minute period and the flame front shall not progress more than 10.5 feet beyond the centerline of the burners at any time during the test.