Legal issues for loan on joint property

My Self and my mother own a Commercial Property jointly. The Property can be described as the Entire 1st Floor of a Commercial Building which is a hall type floor plate measuring 4300 Sq Ft owned in the ratio of 80:20 (Son: mother) I want to avail a bank loan on the said property,but the bank wants my mother to sign as a guarantor for the property because of the nature of the ownership. I want to keep my mother away from signing as guarantor for the loan - Is there a way out for this problem? Can experts find a way out for this problem.