7-20-60 Wildfire Hazards

This section establishes the standards for development in wildfire hazard areas. The level of hazard is determined primarily by grade or slope and continuity of fuels. As a general guideline, low hazard is located on slopes of zero to twenty (0-20) percent with discontinuous fuels; moderate hazard is located on slopes of ten to twenty (10-20) percent with continuous fuels, or on slopes greater than twenty (20) percent with discontinuous fuels; and severe hazard is located on slopes of greater than twenty (20) percent with continuous fuels.

(a) Wildfire Hazards Map

Areas of “Severe Wildfire Hazard” and “Low to Medium Wildfire Hazard” are designated on the Pitkin County adopted Wildfire Hazard Area Maps, which are maintained in the Community Development Department. However, the maps are only a general reference, and actual wildfire hazards shall be field verified. In the event field verification identifies areas of wildfire hazard not identified on such maps, the provisions of this Sec. 7-20-60 shall apply to such areas. In each case where an applicant’s property is located partially or entirely within an area of “Severe Wildfire Hazard”, a wildfire expert acceptable to the County, shall visit the property to evaluate the level of risk in more detail. The wildfire expert may confirm the levels of risk indicated on the Wildfire Hazard Area Maps, or may recommend that all or a portion(s) of the site be reclassified to a higher or lower level of wildfire risk. In addition, the wildfire expert shall make recommendations regarding any mitigation measures that should be implemented in light of the proposed activity or development, and such recommendations shall be considered by the County in the Site Plan process.

(b) Wildfire Hazard Area Delineation and Activity Envelope

If requested by the Community Development Department during a pre-application conference, the Site Plan shall delineate all areas of “Severe Wildfire Hazard” and “Low to Medium Wildfire Hazard” within the Activity Envelope and within one hundred (100) feet outside the Activity Envelope. In the case of varying hazard levels within the Activity Envelope, it shall be sufficient to label the entire Activity Envelope with the highest level hazard existing in any part of such area. The Activity Envelope should be designed to avoid areas of “Severe Wildfire Hazard”, and to mitigate wildfire hazards in areas of “Low to Medium Wildfire Hazard” as set forth in this Sec. 7-20-60. All wildfire mitigation and creation of defensible space shall occur within the Activity Envelope.

(c) Standards Applicable to All Wildfire Hazard Areas

Development is allowed in wildfire hazard areas subject to conformance with the following development standards, (which may be varied upon recommendation by the wildfire expert), and conformance with the additional standards in subsection (d) as applicable.

Defensible Space
Access
Water Supply for Fire Safety
Roofing Materials, Roofing Vents and Projections At and Below Roof Line

Unless the wildfire expert has recommended a different method of construction, roofs and projections at or below roof line in Low, Medium and Severe Wildfire Hazard Areas shall be constructed according to the following specifications:
- (a) Low Hazard Area
  1. Roofing Materials
    - a. Class A covering or Class A Assembly as defined by the currently adopted Building Code.
    - b. No wood shakes or shingles.
    - c. All other adopted Building Code compliant methods and materials permitted.

(b) Medium Hazard Area
1. Roofing Materials
  - a. Class A covering or Class A Assembly as defined by the currently adopted building code.
  - b. No wood shakes or shingles.
2. Roof Venting
  - a. Soffit venting shall be located in the outer 1/3rd portion of the overhang.
  - b. Attic, soffit and other roof venting shall be of non-corrosive metal mesh with maximum ¼” openings.
3. Projections at the Roofline, including Soffits, Rafters, Porch or Deck Roofs, Fascias, or Other:
  - a. Sheath with non-combustible materials, or
  - b. Combustible materials underlain with 5/8” Type X gypboard or equal, or
  - c. Minimum 4x6 rafters with 2x T&G decking.
4. Decks, Decking, Cantilevered Floors, or Other Projections Below the Roofline:
  - Minimum 6x6 posts, 6x10 beams, 3x8 joists, 3x decking, and 2x railings, or equivalent log construction.
5. Other
  - Any methods approved for Severe Wildfire Hazard Areas may be used in Medium Wildfire Hazard Areas.

(c) Severe Hazard Area
- All requirements for Medium Wildfire Hazard Areas apply with the following modifications:
1. Roofing Materials:
  - (a) Class A covering or Class A Assembly as defined by the currently adopted building code.
  - (b) No wood shakes or shingles.
2. Projections at the Roofline, including Soffits, Rafters, Porch or Deck Roofs, Fascias, or Other:
  - (a) One (1) hour rated material or any material underlain by 5/8” Type X gypboard or equal, or
  - (b) “Type IV” Heavy Timber materials, per the currently adopted building code.
3. Decks, Decking, Cantilevered Floors, or Other Projections Below the Roofline:
  - (a) Construction with noncombustible or one (1) hour rated material, or material with flame spread <25 (tested to ASTM E84 and listed for exterior use), or
  - (b) Conventionally framed deck with waterproof surface and underside protected with 5/8” Type X gypboard or equal (decking as “a” above), or
  - (c) “Type IV” Heavy Timber materials: joist and beams minimum 6”x10”, columns minimum 8”x8”, decking minimum 4” in depth, or decking as ”a” above; or equivalent log construction, or
  - (d) Enclose projection vertically to ground with one hour fire resistive materials. Decking as ”a” above.
4. Railings
  - Railings must be constructed of noncombustible or “Type IV” Heavy Timber materials.
5. Exterior of the Structure, Including All Walls
  - (a) One (1) hour fire resistive rated materials, or 5/8” gypboard underlying combustible materials, or
  - (b) Cement stucco, minimum ¾” thickness.
  - (c) All glazing to be tempered glazing; and
  - (d) Doors to be metal or wood 1 ¾” thick minimum.
6. Foundations
  - Foundations, skirting, and crawl space openings shall be fully enclosed and constructed with materials approved for one (1) hour fire-resistive construction on the exterior side of the walls and shall extend from the top of grade to the underside of the floor decking or walls.

(d) All Hazard Areas
- Roofs with less than a 3:12 pitch are not permitted in Low, Medium, or Severe Wildfire Hazard Areas unless they comply with the following:
  1. All roof coverings shall be constructed of non-combustible materials and installed on a Class A roof assembly.
  2. All roof coverings shall have a surface that shall facilitate the natural process of clearing roof debris.
  3. Protrusions above the rooline, such as parapets, shall be prohibited.
  4. Roofs shall be installed as required by the adopted Building Code and shall have a minimum pitch of 1:48.
  5. All roof designs, coverings, or equivalent assemblies shall be specifically approved by the Fire Marshall prior to submittal of a building permit application.

5. Maintenance and Miscellaneous Requirements

(a) Roofs and gutters shall be kept clear of debris.
(b) Roof vents shall be screened with corrosive resistant wire mesh, with mesh one-fourth (¼) inch maximum.
(c) Yards shall be kept clear of all litter, slash and flammable debris.
(d) All flammable materials shall be stored on a parallel contour a minimum of fifteen (15) feet away from any structure.
(e) Weeds and grasses within the ten (10) foot perimeter shall be maintained to a height not more than six (6) inches.
(f) Firewood/wood piles shall be stacked on a parallel contour a minimum of fifteen (15) feet away from the structure.
(g) Swimming pools and ponds shall be accessible by the local fire district.
(h) Fences shall be kept clear of brush and debris.
(i) Wood fences shall not connect to other structures.
(j) Fuel tanks shall be installed underground with an approved container.
(k) Propane tanks shall be buried, if possible, or installed according to NFPA 58 standards and on a contour away from the structure with standard defensible space vegetation mitigation around any aboveground tank. Any wood enclosure around the tank shall be constructed with materials approved for two (2) hour fire-resistive construction on the exterior side of the walls.
(l) Each structure shall have a minimum of one ten (10) pound ABC fire extinguisher.
(m) Addresses shall be clearly marked with two (2) inch non-combustible letters and shall be visible at the primary point of access from the public or common access road and installed on a non-combustible post.
(n) Additional recommendations from the Colorado State Forest Service, the Pitkin County Sheriff’s Department, the local fire protection district and/or a person certified by the Community Development Department as an expert in designation of wildfire areas and wildfire mitigation may be incorporated into any conditions of approval as necessary to mitigate wildfire hazards.

(d) Additional Development Standards for Severe Wildfire Hazard Areas

Development is prohibited within or immediately adjacent to any Severe Wildfire Hazard Area, unless it is determined that: (1) there is no alternative development area on the property that is free of "C--Severe Hazard: Trees" or "X--Severe Hazard: Brush" wildfire hazards; or (2) development within the Severe Wildfire Hazard Area is preferable to alternative Low to Medium Wildfire Hazard site(s) because of other hazard concerns relating to the alternative site(s).
Development permitted in Severe Wildfire Hazard Areas pursuant to this section shall be subject to all of the standards of Sec. 7-20-60(c) above.

(e) Recommendations of Wildfire Expert

In the case of both “Severe Wildfire Hazard Areas” and “Low to Medium Wildfire Hazard Areas”, the wildfire expert is authorized to recommend that mitigation be provided through any combination of the structural design and construction techniques and the defensible space techniques identified in this Sec. 7-20-60.

7-20-60 Wildfire Hazards

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