A glazed roof having a ridge and at least one free ridge end has a ventilation path through a ridge end component. Typically a Victorian or Edwardian style conservatory will have one or more ridge ends suitable for adoption of the present invention. At such a ridge end, glazing bars (19) extend downwardly and radially, a cover (20) sits over the ridge end and a decorative finial (38) is mounted on the cover. It is proposed that a generally vertical ventilation tube (24) be provided at the ridge end. Then the finial or other decorative cover may be fitted over the ventilation tube leaving a space between edges thereof through which air can escape.