Claiming rehab expenses on taxes

[Spencer Small]

Two questions on this:

1. On line items below the $2500 threshold for an expense.  I paid 2/3 of a renovation during the 2019 tax year with the remainder due here in 2020.  Do I just use an excel sheet to take 2/3 of each line item below the threshold as the expense amount?

2. On line items above the $2500 threshhold for an expense.  I paid 1/3 of another renovation in 2019 tax year.  For example the line item cost for refinishing all hardwoods was $4400.  So can i take 1/3 of that cost and deduct it as an expense since it's under the $2500?  Then in 2020 I would because the 2/3 would be under the $2500?

Any help would be appreciated. Thanks.