I've noticed that the base of my rooftop tent is beginning to crack in spots, particularly where the ladder is used to fold it out and back in, and where the ladder rests in transit. Structurally it's stable, as the aluminium surround keeps it all held together, but at some stage in the future I'd like to replace it.

Anyone know what material ARB use to manufacture their tent bases? It seems to be some kind of honeycomb sandwiched between either aluminium or plastic, depending on the sheet. And where, if anywhere, it is available??