How can I calculate perm rating for a TILE floor with GROUT lines? .06 perms
I am working to retroactively permit an ADU. The jurisdiction uses an ADU conversion to impose a .06 perm rating requirement for a slab floor. But this floor has 12*24 glazed ceramic tiles probably over redgard. Humidity is good, and it seems the place is doing fine.
The question is how could I convincingly and correctly document, calculate or measure the perm rating of this assembly, in a way that might seem convincing to the building official?
Or would you recommend just hiring a crew to tear up the tile not breaking as many as possible, add another layer of redgard then reinstall the tile.
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