How do we calculate the amount of depreciation for $9020 to reroof our duplex? Where should we enter this?

[Hal_Al]

You use the same ratio of rental to personal that you used when you set up the original building depreciation. For example if your residence unit is 60% of the sq. ft and the rental 40%; you only depreciate 40% of the $9020.

if the contractor broke down his invoice to show the cost to remove the old roof, 40% (using the example) of that cost may be written off as an expense. Even if the contractor did not provide a breakdown, you may use a reasonable estimate.

Furthermore, if the old roof was not fully depreciated, you may write off the remaining depreciation. You may do this even if the roof was not originally set up as a separate depreciable asset.   For a detailed explanation see: https://www.thebalance.com/partial-dispositions-3192873

As you can see, you have a complex situation.  You may want to have your taxes done professionally this year.

[HelenaC]

Residential rental's are depreciated over 27.5 years. Your roof will have the same depreciation years as your rental, 27.5 years. TurboTax will calculate the annual depreciation amount when you enter the roof (improvement) as an "asset to depreciate" in the rental section of TurboTax. 

• Improvements are depreciated using the straight-line method, which means that you must deduct the same amount every year over the useful life of the roof. The IRS designates a useful life of 27.5 years. 

Please read the information and how to enter your roof: https://ttlc.intuit.com/replies/4791833