Abstract: Apparatus is disclosed for ventilating a roof space or attic, particularly at the ridge or along the hip of the roof. The apparatus includes support members for supporting and spacing roof ridge tiles or cover elements above the roof surface at the ridge or hip. The ridge or hip and the support members have vent openings for passage of air therethrough and out from under the ridge or hip tiles. The support members straddle the ridge or hip and have longitudinal side portions with outwardly disposed louvres. The support members also have central, inverted-V inner portions connecting the side portions at the respective bases thereof. The inner portions have upper louvres and shield portions located adjacent to the side portion louvres to prevent precipitation from passing in through the support members and down through the roof ridge vent openings.