Abstract: This invention relates to inflatable shelters of the kind that are formed from flexible impervious material, such as plastic, treated fabric, or the like, and which are so constructed as to embody in a unitary structure a skin for the closure and inflatable tubes constituting supporting frame ribs. In particular, the invention teaches a new and relatively inexpensive method of producing the rib tubes, particularly at their points of intersection or crossing and of establishing or avoiding the establishment of intercommunication between tubes which so intersect or cross, as may be dictated as preferred in any particular shelter structure.