To provide flexibility following sufficiently the deformation of base isolation rubber and high heat resisting and insulating properties by forming a heat resistant covering for base isolation laminated rubber, of a hardened silicone rubber composition.

A fire resistive covering 13 for base isolation laminated rubber 12 is formed of a hardened silicone rubber composition. The hardened silicone rubber composition is a laminate or a composite of a hardened foaming silicone rubber composition 14 and a hardened non-foaming silicone rubber composition 16. Preferably the elongation of the hardened non-foaming silicone rubber composition at the time of rupture is 50% or higher. Preferably the density of the hardened foaming silicone rubber composition is 500 kg/m3 or higher. Thus a fire resistive covering having flexibility that can follow sufficiently the deformation of the base isolation laminated rubber 12 and high heat resisting and insulating properties.