sealing expansion joints/painting basement floor
We have a partially finished basement (DIY), but what isn't finished is all concrete. Our home is 10 years old. Eventually we would like to finish off the rest (as we can afford to), as we have plans of a game room/rec area in the larger unfinished part, which is also exposed and has a window and patio door going outside. Such a nice area to NOT be using!
When they put in the concrete, they put in what I'm learning are called "expansion joints" in the floor, right down the middle of it... which I'm wondering if those could be filled in with some sort of epoxy filler? Will that do any harm? My husband says they are there for a reason, well, I would think the floor is 10 years old now, and doesn't see much for temperature fluctuations like it would outside, so we should be ok.
At first I thought carpet, but now that I am seeing that there is so much that can be done with a concrete floor and epoxy paints, I am thinking about keeping it simple and painting the concrete instead of covering it with carpet. Hence my question about filling in the joints (if covering with a pad and carpet, I wouldn't care so much, we did just cover them up in the rooms that are built and finished).
So I'm reading everything I can about painting the floor... and one site said I needed to prime it first, with a mansonry primer, then "etch" the floor prior to painting? Can anyone who's done a floor such as this enlighten me? If I were doing my garage floor, I wouldn't care so much about being absolutely perfect...but seeing as though this is inside the house, where we would at times entertain, I really want to do it right the first time.
Thanks for any feedback!