[Festus2]

IF you were to get up on the roof, you can "find" the trusses by applying downward pressure with your foot onto the rubber roof. The roof will flex somewhat between the trusses and will flex very little, if any, where the cross-members are located.

Sometimes, if you look at the roof at just the right angle, you can detect faint "lines" where the various roof sections are divided. You may also be able to "feel" them by sweeping the palm of your hand across the roof.

The rubber membrane, of course, is laid on top of the roof sheathing so you will not see or feel any screws. If you do, then you have trouble!