What is the difference between

Я буду убирать квартиру (imperfective future)

I will clean the room (once and then again afterwards?)

and

Я буду убрать квартиру (perfective future)

I shall clean the room ( and only once!!)

and

Я уберу квартиру (perfective present)

I'm going to clean the room just now ( and only once!!)

Thanks a lot