The premdor north american maple veneer internal fd60 fire door has a solid core and is finished with a factory lacquered maple veneerthis door provides 60 minutes of fire protection when hung in accordance with the manufacturers instructions in an appropriate frame with intumescent strips in the jambs and head or top and long edges of the door click on the video link under the product image for more details on installing fire doors please note all veneers are natural products and some va