Your lease will outline whether the freeholder has any responsibility for repairs. If you own a leasehold flat the freeholder may be responsible for repairs to the structure of the building, or shared areas. If you own a leasehold house it is unlikely that your freeholder will be responsible for repairs.
You should report any damage or disrepair to your landlord immediately. It's always a good idea to follow up any reports you make over the phone or in person with a letter so both you and your landlord have a record of any work that needs to be done.
It can be tempting to stop paying rent if you feel the property you are renting is not up to standard or the landlord is not sticking to the tenancy agreement. This is a risky procedure as your landlord may try to evict you if you stop paying rent.