Holidays over, it is time to get serious about the deck.
I did some experiments (on the garage floor) with plywood and 4x4 timbers. To
avoid excess movement/bounce/sag, the plywood covering has to be of reasonable
thickness and well supported. Less of one means more of the other and somewhere
in the equation will be the minimum cost point!
But let’s be practical.
Our first plan
was to use short lengths of scaffolding plank jammed between the deckhouse and
the first part of the gunwale at intervals of 4ft (Photo). That is supposed to
represent bitumen between the planks, not water! The insulation would fit
between the planks and the whole lot covered with plywood from deckhouse to the
main part of the gunwale. The plywood would be supported by and fixed to the
planks and to the gunwale.
However, my
experiments showed that on the deckhouse side, supported every 4ft, there would
be definite sag unless the plywood was quite substantial (expensive). This
would crush the insulation boards beneath and allow bounce. The other problem
with the plank idea was that they would have to be doubled up to provide the 4
inch height needed to match the gunwale step. It would also degrade the
insulation every 4ft for 9 inches, albeit slightly. (Photo)
The second
thought was to run a 4x4 along the side of the deckhouse and use that to
support the plywood throughout its run along the sides (Photo). The unsupported
distance would be across the width and be only about 20 inches. There would be little
or no sag and no break in the insulation.
The other
practical point concerns the problem of rain interrupting the process. The ship
(deck) is slightly banana-shaped so that water gathers amidships and drains
through the holes you can see in the photos. If we have the side decks raised
with timber and insulation and it rains, there will be large puddles at the bow
and stern, which will have to be drained somehow before we can begin in those
areas. So we will do them first. The stern is fairly straightforward and a simple
grid of 4x4 will be fashioned to support the plywood. The bow is more
complicated due to the companionway and the hawspipes (nostrils). Necessity is
the mother of invention! (Photo)
The numbers
indicate how many 2.1m x 1.2m insulation panels are going to be needed
(roughly!). There will be off-cuts aplenty to fill in the awkward bits.
David.
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