The image above illustrates a section of the
Motorhome floor. A plywood sheet top and bottom with Polystyrene in
between. It also has timber battens to increase strength.
This construction method makes for a strong
and very light build required in the Motorhome. Any extra weight is
the weight removed from the Motorhome owner's carrying capacity.
The construction method has a problem! after years of walking over
it the polystyrene compresses, leaving the plywood to move up and
down, thereby increasing the damage and weakening the floor structure.
The only answer is to fill the gap between
the compressed polystyrene and the plywood. There are 'Packs'
available from Motorhome repair dealers to enable the experienced DIY
man to carry out a repair.
Recently with this problem, I have decided
to leave the job to an experienced caravan repair shop, as the floor
damage was in the section from the entry door, in a large circle.
So if you have a spongy section in your
floor, get it repaired as soon as possible.
The test method used by my repair man was to
walk on his heals, gently, the floor could then be seen moving up and down.