Section 179 Depreciation

When Turbotax figures my section 179 depreciation on a 27,985 roof replacement is says I only have $90 of income to deduct from therefore that is all I can deduct.  I show that the business has over $45,000 in profit.  

Why am I only getting $90 to depreciate this year & then it is showing depreciating the rest over 39 year?