How big does the header need to be for a 5' span of a non-load-bearing wall? And what size for cripples? We have a closet with a regular 36" door and we'd like to open it up to have space for a set of 60" bifold doors. (so, total opening is about 62".
You don't indicate where you are located, so we have no idea which building code you need to follow. Check with your local code enforcement official, or purchase a copy of your building code, it should have full information about minimum header size for a non-load bearing condition.