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The provisions of Chapter 4 [CE] of the International Energy Conservation Code are adopted by reference and shall apply with the following modifications:
1. C402.2.2 Roof assembly. Revise to read:
C402.2.2 Roof assembly. The minimum thermal resistance (R-value) of the insulating material installed either between the roof framing or continuously on the roof assembly shall be as specified in Table 402.1.3, based on construction materials used in the roof assembly. Skylight curbs shall be insulated to the level of roofs with insulation entirely above deck or R-5, whichever is less.
Exceptions:
1. Continuously insulated roof assemblies where the thickness of insulation varies 1 inch (25 mm) or less and where the area weighted U-Factor is equivalent to the same assembly with the R-value specified in Table C402.1.3.
2. Where tapered insulation is used with insulation entirely above the deck, the R-value where the insulation thickness varies 1 inch (25 mm) or less from the minimum thickness of tapered insulation shall comply with the R-value specified in Table C402.1.3.
3. Unit skylight curbs included as a component of a skylight listed and labeled in accordance with NFRC 100 shall not be required to be insulated.
4. For roofs on existing buildings with a slope of less than 2.5 units vertical in 12 units horizontal (2.5:12), refer to Section C503.1 exceptions).
5. For roofs on existing buildings, refer to Section C503.2 or C504.2.
2. C402.3 Roof solar reflectance and thermal emittance. Delete existing C402.3. Insert a new C402.3, titled “Urban heat island provisions”:
C402.3 Urban heat island provisions. The following are exempt from the reflectance requirements:
1. The portion of the roof acting as a substructure for and covered by a rooftop deck, or vegetation associated with an extensive or intensive green roof as defined by the U.S. Environmental Protection Agency (“USEPA”), or by photovoltaic and solar thermal equipment.
2. A rooftop deck covering a maximum of 1/3 of the rooftop total gross area.
The remainder of the roof area must meet the reflectance requirements set forth in this section.
3. Table C402.3 Minimum Roof Reflectance and Emittance Options. Delete existing Table C402.3.
4. C402.3.1 Aged roof solar reflectance. Delete existing C402.3.1. Insert a new C402.3.1, titled “Solar reflectance”:
C402.3.1 Solar reflectance. All roof exterior surfaces shall have a minimum solar reflectance as specified in Section C402.3.2 through C402.3.5 when (i) tested in accordance with ASTM E903 or ASTM E1918, (ii) tested with a portable reflectometer at near ambient conditions; (iii) labeled by the Cool Roof Rating Council, or (iv) labeled as an Energy Star qualified roof product. Any product that has been rated by the Cool Roof Rating Council or by Energy Star shall display a label verifying the rating of the product.
5. C402.3.2 Low-sloped roofs. Insert a new C402.3.2, as follows:
C402.3.2 Low-sloped roofs. Roofing materials used in roofs with slopes of a rise of 0 units in a horizontal length of 12 units (0:12 pitch) up to and including roofs with slopes of a rise of 2 units in a horizontal length of 12 units (2:12 pitch) (“low-sloped”) shall meet the following requirements:
1. Low-sloped roofs permitted on or after April 22, 2009 in conjunction with a new building or structure shall utilize roofing products that meet or exceed an initial reflectance value of 0.72 or a three-year installed reflectance value of 0.5 as determined by the Cool Roof Rating Council or by Energy Star.
Exception: Where more than 50% of the total gross area of the low-sloped roof is covered with vegetation associated with an extensive or intensive green roof as defined by the USEPA, the remainder of the roof shall have a reflectance value of a minimum of 0.30. The rooftop deck exception in C402.3 applies.
Exception: Ballasted roofs with a minimum of 15 lbs/sq. ft. of ballast over the entire roof surface may have a reflectance value of a minimum of 0.30. For purposes of this section, “ballast” shall mean river rock aggregate or larger, pavers or other means of weighing down a roofing membrane over a substrate to resist wind uplift.
6. C402.3.3 Medium-sloped roofs. Insert a new C402.3.3:
C402.3.3 Medium-sloped roofs. Roofing materials used in roofs with slopes of over a rise of 2 units in a horizontal length of 12 units (2:12 pitch) up to and including roofs with slopes of a rise of 5 units in a horizontal length of 12 units (5:12 pitch) (“medium- sloped”) shall have an initial solar reflectance of 0.15 or greater.
7. C402.3.4 Multiple-sloped roofs. Insert a new C402.3.4:
C402.3.4 Multiple-sloped roofs. Roofs with multiple slopes shall be subject to those requirements applicable to the slope which covers the largest area of the building footprint.
8. C402.3.5 Steep roofs. Insert a new C402.3.4:
C402.3.5 Steep roofs. Roofs with slopes greater than a rise of 5 units in a horizontal length of 12 units (5:12 pitch) shall be exempt from any initial solar reflectance requirements.
9. C402.5.1 Air Barriers. Revise to read:
C402.5.1 Air Barriers. A continuous air barrier shall be provided throughout the building thermal envelope. The air barriers shall be permitted to be located on the inside or outside of the building envelope, located within the assemblies composing the envelope, or any combination thereof. The air barrier shall comply with Sections C502.5.1.1 and C502.5.1.2. For roof air barriers on existing buildings, refer to Section C503.1 or C504.2.
10. C402.5.1.1 Air barrier construction. Revise to read:
C402.5.1.1 Air barrier construction. The continuous air barrier shall be constructed to comply with the following items (1) through (3), inclusive. The air barrier shall be continuous for all assemblies that are the thermal envelope of the building and across the joints and assemblies.
1. Air barrier joints and seams shall be sealed, including scaling at joints between dissimilar materials. The joints and seals shall be securely installed in or on the joint for its entire length so as not to dislodge, loosen or otherwise impair its ability to resist positive and negative pressure from wind, stack effect and mechanical ventilation.
2. Penetrations of the air barrier shall be caulked, gasketed or otherwise sealed in a manner compatible with the construction materials and location. Paths for air leakage from the building to the space between the roof deck and roof covering used air barrier, shall be caulked, gasketed or otherwise covered with a moisture vapor-permeable material. Joints and seals associated with penetrations shall be sealed in the same manner or taped or covered with moisture vapor- permeable wrapping material. Sealing materials shall be appropriate to the construction materials being sealed and shall be securely installed around the penetration so as not to dislodge, loosen or otherwise impair the penetrations' ability to resist positive and negative pressure from wind, stack effect and mechanical ventilation. Scaling of concealed fire sprinklers, where required, shall be in a manner that is recommended by the manufacturer. Caulking or other adhesive sealants shall not be used to fill voids between fire sprinkler cover plates and walls or ceilings.
3. Recessed lighting fixtures shall comply with Section C402.5.8. Where similar objects are installed that penetrate the air barrier, provisions shall be made to maintain the integrity of the air barrier. Light fixtures installed within environmental air spaces shall meet the requirements of the Chicago Building Code.
(Added Coun. J. 9-14-16, p. 31143, § 1)