I've put the mounts on my solar panel and have just put it on the roof of the MH (not stuck). I notice that the mounts do not all sit flush with the roof (i.e the bases are not parallel to the roof). Does this matter, as long as I get a minimum of 2mm clearance with a spacer where the mounts touch the roof. I should think the amount of "gap" I have is about 2 to 3 mm max. I'm using Sikaflex 521.