I was building a metal building near Kingsbury Tx Jan/Feb 2006. We were installing roof panels when I noticed something hovering in the air behind two of my crew members that were already on the roof. I observed the object for several minutes while waiting on the next sheet to be pre-drilled inside the garage. When the next sheet was ready, I slide the sheet up and onto the garage roof over my head losing sight of the object. When the sheet was past my head and my line of sight was clear again, the object was gone. I honestly thought is was a US Airways plane (unpainted, silver, and shiny in color) but it didn’t seam to move and I couldn’t see any wings, tail, or engines. It made no noise (could have been too far away) -and left no jet-stream. Things I looked for as I am a retired Air Force jet engine mechanic and I’ve been around lots of aircraft. My second thought was that it was the Metlife blimp but again, it just seamed to hover in place. I don’t know if this is worth an investigation but I wanted to tell my story to someone besides my family.