E04D13/00
Special arrangements or devices in connection with roof coverings; Protection against birds;; Roof drainage; ; Sky-lights;
E04D13/00
Special arrangements or devices in connection with roof coverings; Protection against birds;; Roof drainage; ; Sky-lights;
E04D13/17
Ventilation of roof coverings not otherwise provided for
E04D13/17
Ventilation of roof coverings not otherwise provided for