20k Tile Vent is a Universal Tile Vent that suits most concrete interlocking roof tiles that can be used to ventilate roof voids. Installation guide The Tile Vent is positioned inline with the tile below and an opening is cut in the underlay using the template provided. Once the opening has been made in the underlay the back box is inserted through the opening until the Tile Vent nibs are located over the top of the batten. The Tile Vent is then fixed into the batten through the nail hole within the Tile Vent and with the wire clip provided. The front skirt is dressed onto a clean dry tile surface. The roof tiles either side of the vent are then laid. Prior to the tile above the vent being laid the upper skirt needs to be pushed down. Tile battens would need to be cut if plain tiles are being used. Properties Material: soft and rigid uPVC. Colour: slate. Regulations and certifications Complies fully with relevant Building Regulations and British Standards. Please note the Universal Tile Vent does not suit the following tile profiles: Redland Delta, Cambrian, Saxon, Richmond; Anchor Centurion, Slate; Marley Monarch; Clay Pantiles; Landmark Slates.