Dupont says not to tape/seal plywood seams???
I was doing a bit of research about sealing plywood seams on a retrofit project…I stumbled across this on Tyvek’s FAQ page:
15. Can I tape sheathing board seams?
Taping sheathing board seams creates a continuous vapor barrier, so moisture vapor would have no where to escape. Adhesion of tape to foam and wood would also be temporary, due to thermal expansion and contraction of the wall assembly. A more effective and efficient means to provide air infiltration resistance and bulk water holdout is to properly install DuPontâ„¢ Tyvek¯ using our best practice guidelines. Since DuPontâ„¢ Tyvek¯ flexible, it will continue to provide protection to the sheathing when undergoing thermal expansion and contraction.
Is this true? Seems like it would be wise to tape the seams – does this make it a vapor impermeable as Dupont suggests? Then read Martin’s blog and saw that Marc Rosenbaum recommends using Vycor to tape seams. Hmmm. I’m in Climate Zone 3.
Thanks for guidance,