1. Verify sizing

• Venting system shall be sized and constructed so as to develop a flow adequate to convey all combustion products to the outdoors.

2. Venting materials

• Materials for vents and vent connectors shall be installed to resist the corrosive action of flue gasses and condensate.

3. Single-wall venting

• Single-wall metal pipe shall not originate in any unoccupied attic or concealed space.

• Shall not pass through attic, inside wall, concealed space or floor.

• Must have 6 inches of clearance to combustible material.

• Venting shall have a rise of 1/4" per linear foot.

• Joints and connections to flue collar or draft hood outlets shall be fastened by sheet metal screws or other approved methods.

4. Metal liners for masonry chimneys

• Install liner in unlined masonry chimneys or chimneys with deteriorated liners.

• Use a correctly sized Type-B vent, a flexible or rigid stainless steel liner, or a flexible aluminum liner.

• If installing flexible aluminum liner comply with the manufacturer’s instructions, which usually require stretching the liner and fastening it securely at both ends, to prevent the liner from sagging and creating a low spot.

5. B-vent

• Where venting passes through insulation in attic, an insulation shield constructed of steel shall be installed to provide a minimum of 1 inch clearance between the vent and insulation, and not less than 2" above insulation material.

• Venting shall have a rise of 1/4" per linear foot.

• Venting shall be securely supported for the design and weight of materials and maintain proper clearances.

• Screws, rivets and other fasteners shall not penetrate inner wall of B-vent.

6. B-vent termination

• Venting shall extend through a flashing.

• Termination height shall be in accordance with the IFGC Section 503.6.5.

• Vents shall terminate with a listed cap (IFGC 503.6.7).

7. Worst Case Draft test

• Conduct a Worst Case Draft (WCD) test to verify Category I, II, and III appliances are venting safely before leaving home for the day.

• Testing shall be recorded using the Utah WAP Worst Case Draft Test form.

RMGA certified technician

Work done on natural gas burning appliances must be done by a Rocky Mountain Gas Association Certified Technician.