Garage fire claim denied

[Vladimir Nemchinov]

Hello there everybody,

I own a property that is my primary residence. There are two garages, one i rent to a guy who is a contractor and stores his materials there. Two weeks ago it caught on fire. My insurance company says it was his fault and since it was rented out to "business" they would  not cover the claim. His insurance says they refuse to cover it. All I am concerned about is structure, which, since, insured in my policy, I thought, was covered. 

1 Am I stuck with the repairs right now? Or can I contest it somehow? 

2 If you have any thoughts please share. 

Thank you!