Caravan floor delamination

LeTouriste

This subject crops up from time to time and, from recent posts, it seems that it will not diappear in the near future.  One recommended solution is that of inserting resin between the floor skin and the bearers inside the 'sandwich'.  I have often wondered
how that resin is inserted to spread across the two faces that are to be reglued.  What is the width of these bearers?  How can anyone be sure that the resin spreads evenly across the faces to be glued, or simply goes a small way across part of the face, and
the remainder just ooze between the bearer and the insulation in the cavity between bearers.