Barrier coating mixtures include (a) a non-butyl elastomeric polymer; (b)
an acid or base treated dispersed, substantially exfoliated silicate
filler material that has not been functionalized with organic cations
having an aspect ratio greater than 25; and (c) at least one additive,
wherein the total solids content is less than 30% and the amount of
filler is between 5% to about 60% of the total solids content. The
coating retains its permeability properties under strain and has a strain
to first damage of at least 5% biaxial elongation at 0% RH.