the house that i bought has unfinished drywall in the basement and it all needs to be taped. There is some spots that have about 1/2 inch gap between the sheets. Should i fill them with compound first and let it dry and sand or would it be ok to just start the tape job.
A 1/2 inch gap is pretty easy to deal with if you use setting type compound. This is a dry mix that has a setting time labeled on the package of 20, 40, 60 or 90 minutes. I like 40 for most jobs, but if you need more or less working time buy accordingly. Fill the cracks with compound, apply the tape, then embed the tape. Finish normally with either setting or premixed joint compound.