There are several explanations as to why warehouse clubs charge membership fees and. how the fees play a role in the competitive landscape of the retail grocery market. We provide. another insight into the nature of the membership fee using a model of price competition. between a warehouse club and a supermarket.
A prescriptive ignition barrier is required within a residential application over the surface of the polyurethane foam insulation when used within accessible attics or crawlspaces. Interior surfaces in inhabited buildings should be covered with a 15 minute thermal barrier for fire protection.
Ignition barriers, on the other hand, are required in foam-insulated attics, crawlspaces, and other areas with limited access that canât be used as living space. They offer a lower order of protection, and are intended simply to prevent a possible flame source from making direct contact with the foam.