Seal and sound insulation sheet for a vehicle body élément, such as a car door

The sheet (16) has a face including a cord (20) extending along a peripheral edge of a layer (22) for fixing the face on a support e.g. sheet metal. A rigid, corrugated frame work (18) is applied to another face (24) of the sheet along the peripheral edge in alignment with the cord. Screws (26) fix the frame work to the support and ensure the compression of the cord on the support.