you actually sold the roof because you sold the property it was attached to. the easiest way to handle this in TurboTax is to allocate from the gross proceeds on sale an amount equal to its undepreciated value so there is no gain or loss on sale.
if you've been using Turbotax since 2018, the depreciation asset class , life and method should already be there for the roof.
don't know how you computed depreciation.
the IRS says the depreciable life for a roof on residential rental is 27.5 years depreciated straight-line so depreciation should only be around 20% of cost.
for each asset of the rental you can go into the asset worksheet to enter sales price and expenses - only available in forms mode which is only supported by desktop versions. In online versions it should be asking the sales price and sales expenses for each asset