It is taxpayers' rights to interpret the law in their favor when the guidance is not completely clear.
It is ultimately your decision how to classify the patio, as a repair or, if substantially enhancing the property, as an improvement. In regards to responding to a potential IRS inquiry, Publication 527 would be the main resource to cite.
Publication 527 does provide parameters for interpretation to apply to your circumstances.
If the property does typically have personal use more than 14 days, see page 17 of Publication 527 for more information on how to allocate rental expenses.
[Edited 05/12/2021 | 9:29 AM PST]
@jonath1021
