I suggest you check the aircraft insurance policy. Some hirers will charge you if the plane is damaged because it increases their insurance costs. Check the hirers rules agreement etc.
The aircraft policy should have third party insurance to cover passengers and persons outside the aeroplane, it will probably not cover you the pilot as you are not a third party.
Beware! there is no UK legal requirement to have aircraft insurance. Most airfields however do have a minimum cover required, which can be up to £5,000,000.