• Work must be performed by a RMGA* certified technician

• *Rocky Mountain Gas Association

2. Verify sizing 

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

3. Venting materials 

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

4. 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 minimum 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. 

5. 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. 

6. 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 minimum 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. 

7. B-vent termination 

• Venting shall extend through a flashing

• Termination height  shall be in accordance with the table in Figure 503.6.5, follow this link to the IFGC Section 503.6.5

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

8. Worst Case Draft Test 

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

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