Factory Floor patchy

Well in the end I followed this tutorial "Baked Lighting" and "Lightmaps" (Maya & Unreal Engine) - YouTube (but didn’t really change my UV setup), I did notice when importing my mesh I had “Generate Lightmap UV’s” & “One Convex Hull Per UCX” on, so I turned those off. I kept my Mesh “Min Lightmap Resolution” & “Light Map Resolution” as 256. And changed my World Settings for “Static Lighting Level Scale” to 0.1 & “Indirect Lighting Smoothness” to 2.

Are any of those settings going to be inefficient, anyhow I got this result…