Airtight elastomeric laminate for tyres, the said laminate comprising at least two superimposed layers of elastomer: ∘ a first layer, composed of a composition based on at least: - a thermoplastic block elastomer comprising at least one central polyisobutylene block and adjacent blocks composed of at least one polymerized monomer, other than a styrene monomer, the content of the said thermoplastic block elastomer being within a range extending from more than 50 to 100 phr (parts by weight per 100 parts by weight of elastomer) and it being understood that the glass transition temperature of the said non-styrene polymer constituting the thermoplastic block of the thermoplastic block elastomer is greater than or equal to 60°C and, in the case of a semicrystalline thermoplastic block, a melting point greater than 60°C, - and on a plasticizing system comprising from 1 to 40 phr of a plasticizing oil and from 1 to 40 phr of a hydrocarbon resin, the total content of plasticizer being within a range extending from 2 to 70 phr, ∘ a second layer, composed of a composition based on at least one diene elastomer, the content of diene elastomer being within a range extending from more than 50 to 95 phr, and on at least one thermoplastic elastomer, the content of thermoplastic elastomer being within a range extending from 5 to less than 50 phr, it being understood that at least 5 phr of the thermoplastic elastomers present in the second layer are compatible with at least 5 phr of the thermoplastic block elastomers present in the first layer. ∘ a first layer, composed of a composition based on at least: - a thermoplastic block elastomer comprising at least one central polyisobutylene block and adjacent blocks composed of at least one polymerized monomer, other than a styrene monomer, the content of the said thermoplastic block elastomer being within a range extending from more than 50 to 100 phr (parts by weight per 100 parts by weight of elastomer) and it being understood that the glass transition temperature of the said non-styrene polymer constituting the thermoplastic block of the thermoplastic block elastomer is greater than or equal to 60°C and, in the case of a semicrystalline thermoplastic block, a melting point greater than 60°C, - and on a plasticizing system comprising from 1 to 40 phr of a plasticizing oil and from 1 to 40 phr of a hydrocarbon resin, the total content of plasticizer being within a range extending from 2 to 70 phr, - a thermoplastic block elastomer comprising at least one central polyisobutylene block and adjacent blocks composed of at least one polymerized monomer, other than a styrene monomer, the content of the said thermoplastic block elastomer being within a range extending from more than 50 to 100 phr (parts by weight per 100 parts by weight of elastomer) and it being understood that the glass transition temperature of the said non-styrene polymer constituting the thermoplastic block of the thermoplastic block elastomer is greater than or equal to 60°C and, in the case of a semicrystalline thermoplastic block, a melting point greater than 60°C, - and on a plasticizing system comprising from 1 to 40 phr of a plasticizing oil and from 1 to 40 phr of a hydrocarbon resin, the total content of plasticizer being within a range extending from 2 to 70 phr, ∘ a second layer, composed of a composition based on at least one diene elastomer, the content of diene elastomer being within a range extending from more than 50 to 95 phr, and on at least one thermoplastic elastomer, the content of thermoplastic elastomer being within a range extending from 5 to less than 50 phr,