ive a set of triples on the van and what i do is, take the base section and ratchet strap it to the roof rack facing the other way to what the other 2 sections will be going.
then the top 2 sections are held in place with a ladder clamp, going all the way through the 3 sections. this way if i need to use the ladder for access, or an average gutter clean, i only have to carry the 2 sections, but the 3rd section is always there if needed, and can be used by undoing a ratchet strap.
hope that makes sence.