1. Ensure clearance from combustibles

• Sweep back any debris or insulation to clear space around chase. 

• Chase should be fully visible. 

• No combustible materials can be within 1" of listed B-vent. 

• No combustible material or sealants shall be within 6" of all other high temperature  penetration. 

• Cut back attic floor if needed.

2. Cut sheet metal 

• On one edge of each piece of metal, trace the shape of the flue to cut out so there will be an overlap of at least an inch once placed together.

• Alternatively, one continuous sheet of metal can be used to cut a hole into the center of the sheet metal that matches the outside of the flue. 

• Strips of sheet metal can be used for rectangular flues.

3. Fabricate fire stop

• Each piece should extend a minimum of 1" around the flue or chimney in a rectangular shape or at least the size to fully cover the chase opening 

• The firestop should secure the vent the required minimum distance from the combustible material while preventing air movement around the vent. 

4. Place pieces around flue

• The cut outs should fit tightly to the flue with an overlap of the two pieces about 1" 

• Fasten to the attic floor with adhesive or fasteners  

5. Seal around all seams

• Using hi-temp adhesive, seal around all the seams in and around the metal pieces. 

6. Create heat shield

• Create a heat shield with sheet metal, metal duct, or insulshield 

• You must size it so that there is enough heat shield material to surround the flue with at least 1 inch  of space between shield and flue; however, less than 3-inch clearance is only allowed if the venting material is "listed and labeled" for less clearance as required by SWS 3.0102.2c. 

• Height of heat shield shall stand a minimum of 2" above final/post-weatherization insulation height. 

7. Secure heat shield

• Heat shield shall surround B-vent flue entirely

• Minimum of 1" space between shield and flue

• Minimum of 6" clearance to chimneys and solid fuel appliance flues. 

• Dovetail heat shield towards the flue or chimneys to protect the shield from compressing. 

• Fasten heat shield to attic floor 

• No debris or materials should be between heat shield and flue. 

8. For non-IC rated canned lights

• Any non-IC rated light fixture will be replaced with an airtight IC-rated fixture or air tight LED insert 

9. Take photos

• Take photo of completed dam before insulation is installed, this is to make sure insulation is not disturbed in the QC or monitoring processes. 

10. 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 form.