Method and device for placing a door humidity shield within a vehicle door

The process involves laying a waterproof sheet provided with an adhesive cord on a liner of a door by applying the cord on the liner. An irregular-shaped part (22) supported by a support plate (23) is applied on the sheet. A pressure is exerted on the part (22) by the plate to squeeze the cord and to fix the sheet on the liner. The sheet and plate are made of flexible and semi-rigid materials, respectively. An independent claim is also included for a waterproof sheet installing device.