In my new construction project, I’m ready to run the dryer vent outside. It’s a 10′ run through the floor joists (parallel) on a second story laundry. I’m using 4″ snap-lock galvanized duct and an inset “Dryer Box”.
The question is, is metallic tape enough at the joints? I’d hate to go through all the trouble of using smooth-wall duct just to have the sharp points of sheet metal screws in the flow path. I can see the screws catching lint in a matter of days.
Is the metallic tape the norm?
My guess is that it would be OK since the assembly is really locked between the exterior wall termination and the Dryer Box and suspended with perforated plumbers tape. The metallic duct tape would just be helping to keep the duct leak-free and not really preventing the ducts from pulling apart.
Thanks!
Jim
Replies
The metallic HVAC tape is enough. Very sticky with backing paper; toughest part is getting the tape stuck on the duct without it sticking to itself.
Our inspectors will not permit any screws in a dryer vent - for exactly the "lint trapping" reason you mentioned.
I usually cut the stuff to length with the paper still on, peel back about 2" or so, wrap it around the duct for alignment and then start peeling and sticking as I go - nice smooth job with a minimum of hassle. I like the tape ends to overlap about 3" or so.
FYI, if you are sticking this stuff down in sub-freezing temperatures, a little heat from a hair dryer of heat gun helps with adhesion. Not too hot, if you can comfortably keep your hand in the heated zone, its about right.
Jim
Never underestimate the value of a sharp pencil or good light.
Drill for pop-rivet
Pop-rivet
duct seal
I'm not too sure about the pop rivit idea since you're still getting a relatively sharp obstruction in the duct. But, I like the duct mastic idea.
Would mastic alone be enough?
Jim
All you need is the tape. The pipe should be well enough braced to hold together, and fasteners of any kind will protrude on the inside. I have never seen a sheet metal man glue pipe together except for one type of gas vent.