To construct or install a roof above or on top of something. A noun or pronoun can be used between "roof" and "over." Often used in passive constructions. Once we roof over the patio, it will be really nice to sit out there in the summertime. I've got the four walls of the shed put together. No I just need to roof it over. We've had a lot more foot traffic in the market now that the square has been roofed over.
roof something over
to build a roof over something; to provide something with a roof. After the destructive storm they had to roof the shed over so that the cow would have some shelter. We will roof over the patio and turn the area into a porch.