Not sure how it is classified, as we never lived in it, but it wasn't used as a rental for 6 months before the sale. We owned it about 5 years.
You should have been using a schedule E while it was a rental. It will be a sale of a rental if it was only vacant (not rented) while it was on the market for sale. If you did something else with it, like one of you lived in it, it stopped being a rental at the time one of you moved in.
Once it was not available for rent (assuming you held it vacant while it was on the market) the expenses associated with it would no longer be rental expenses, they would be added to the basis.
You should have been using a schedule E while it was a rental. It will be a sale of a rental if it was only vacant (not rented) while it was on the market for sale. If you did something else with it, like one of you lived in it, it stopped being a rental at the time one of you moved in.
Once it was not available for rent (assuming you held it vacant while it was on the market) the expenses associated with it would no longer be rental expenses, they would be added to the basis.