Well constructed, however roof system using clips at all angle ends of roof panels is difficult to insert the roof panel into the track. Best way to achieve this is to have one person at the top of the panel, who is on a ladder, guide the panel into the track while the other person is aligning the bottom of the panel. The difficulty lies in the fact that all of the panels are bowed making it difficult to insert the panel into the track while not causing the clips to become dislodged. It is wise to use a drift pin to line up the matching holes and not fully tighten the nuts until the next panel is installed so that there is some slight movement between the panels allowing the hole in the panel to line up with the holes on the track.