Type of Sealant Used on Vent Joints?
#1
Member
Thread Starter
Type of Sealant Used on Vent Joints?
I was in my attic yesterday and noticed that the bathroom exhaust fan vent (and all subsequent joints) had some type of tape(?) to seal the joints.
Haven’t seen this before. Any idea what it is?
Haven’t seen this before. Any idea what it is?
#5
Member
Thread Starter
Whoops, that's what I get for trying to post from the phone. 
Pic is below. Best I can figure is that it is wrapped in fiberglass joint tape with mastic sealant applied on top of that.

Pic is below. Best I can figure is that it is wrapped in fiberglass joint tape with mastic sealant applied on top of that.
#7
Yes, that's ductwork mastic, where I am grey is usually water based and if red would be solvent based.
it is a very durable material .
Can't tell if that is a crack or just a line in the material.
Even though it is strong and stays slightly flexible when dry you need to secure joints with screws before applying.
it is a very durable material .
Can't tell if that is a crack or just a line in the material.
Even though it is strong and stays slightly flexible when dry you need to secure joints with screws before applying.
#8
Just an observation:
I dont see any insulation around the duct or on the ceiling, is that frost on the rafter?
I dont see any insulation around the duct or on the ceiling, is that frost on the rafter?