Recessed light clearences

Hello, I built a soffit in my basement to house some recessed lights, they are non ic recessed lights. My question is how far do they need to be away from combustible materials, I know it says to keep insulation 3" away due to over heating issues, but I wanted to make sure about other clearances. One place I want to put the light, the top of the can will sit very close to the floor joist above. I couldn't build my soffit any deeper due to matching up to an existing soffit.