Tenants obligtions to redecorate

Maintenance

I have a tenant on a month to month hold over RLA Assured Shorthold Tenancy, since January 2010 (original let on a 12 month term). There is much condensation damage to the bathroom, kitchen and especially the attic were I believe an unvented tumble drier has been used. After over 4 years is there any obligation for her to redecorate or do I just rely on the fact that the property be returned in the same condition as it was let to her (save reasonable wear and tear)? I have photographs of its condition when let?