Your case is not unusual and of course I wish you the best of luck in your efforts.
You will see from my entry above on the 25th March that I am aware of this cannabis factory problem and I have to say that from what I have been told from other landlords who have experienced what you have experienced and also from what I know when dealing with insurance companies your chances of a successful claim are finely balanced and more than likely will go against you.
The last Landlord I spoke to had his entire property burnt down and he did not receive a penny from the insurance company and he was through a property Letting Agent as well !
Please keep us all informed of your progress and to all other other Landlords...........
Do you know what your Tenants are up to? When did YOU last have a look at your property?
Mel.