Ko te pepa rapa Butyl he rapa kounga teitei me te werawera teitei. He tino iti te hau me te makuku permeability.Ka whakamahia te pepa rapa Butyl i roto i te maha atu o nga tono, he tino koretake ki te hau, te ozone, te marama puru, te matū me te weath-ering.
