Proper Installation of Bathroom Exhaust Vents

 

	PROBLEM: Steam and water vapor from bath exhaust fan condensing between the collar (flange) and the roof deck causing the plywood of the roof deck to rot.

	Step 1: Remove shingles of old roof, or around bath exhaust vents

	Step 2 and 3: Apply ice and water shield onto the roof deck. Install the collar of the bathroom exhaust vent.  Add another layer of ice and water shield on top of the bathroom exhaust vents.

	Step 4: Add caulking, in a horseshoe shape, on top of the ice and water shield around each collar of the bathroom exhaust vent. It is important to leave lower portion uncaulked to allow condensation to drain freely over protected roof.

	Step 5: Install the bathroom exhaust vent over the caulking, nail as required.

	Step 6: Shingle as required and caulk all exposed nail heads