An installation and a method for selectively producing a single-ply or alternatively a multi-ply nonwoven includes an inclined wire former configured to deposit a sheet of wet-laid fibre material on a first circulating belt, a further belt configured to receive the sheet of wet-laid fibre material from the first circulating belt, a roller card arranged downstream in the material transport direction and configured to introduce a roller card web into the installation, a hydroentanglement arranged downstream in the material transport direction and including at least one water beam configured to entangle, bond and/or structure a single sheet of fibres or a plurality of sheets of fibres, and a dryer arranged downstream in the material transport direction.