Duct tape ok for waterproof underlayment? (laminate, flooring, color, black)

[jellydoboy]

I am installing Floor Muffler underlayment for my laminate flooring over a concrete subfloor (above ground grade). My question is is using duct tape to tape the ends together adequate to maintain the vapor barrier seal? Or would there be other tape you would recommend using? Thanks!

[K'ledgeBldr]

Well, I definitely see your concern-
" If installing the FloorMuffler on concrete or below grade subfloors, be sure to tape the seams together with 2" tape that meets the moisture vapor transmission rate for this type of installation."
What exactly does that mean?
Sounds like an out for their warranty. You'd think they would have their own specific/branded tape.
Duct tape may meet or exceed the vapor transmission rate- Whatever that is. But what does the tape itself do to the underlayment?
I would think that clear packaging tape would have a better/lower transmission rate than duct tape- but again, what would it possibly do to the underlayment itself?

Maybe you should contact the company directly and see what they say- maybe they can clarify their blunder.?

[kodaka]

Per the instructions, step #4:

Seams should be butted together leaving no gaps or overlaps. If installing the underlayment on concrete, or below grade sub-floors, be sure to tape the seams together with two-inch packing tape (for added moisture protection).