Wool carpet is unsuitable for bathrooms. If it persistently gets wet, the backing and underlay deteriorate.  There is no way to waterproof carpet that we are aware of, but you could use a good bath mat to absorb some of the water. Balineum for example, have a good selection, as do Woods of Harrogate. However, it would be far better to change the flooring, even if your home is rented. Carpet can be taken up then relaid once you return your home to the landlord. Flooring that is best suited to bathrooms includes cork, vinyl, linoleum, ceramic and porcelain tiles. See also our ‘Design Topics’ pages for more advice on choosing bathroom flooring.