"John Seager" wrote in message
...
I'm not sure. Simple question - is it usual for deck joints to be butt
joints, or do people use scarf joints? The former seems more likely if the
joints are always over some form of supporting rib.


It is common for production boats to have the butt joint of deck ply on the
deck beams. However, that doesn't mean it is correct. This is because the
grain of the deck beam provides very little strength across the grain. On a
deck of single ply, a scarf or ply butt block between deck beams would be
the correct method.

If the decks were double layers of ply with joints well spaced, then a butt
joint on the deck beam might be expectable since the upper ply acts as the
butt block.

I have never favored plywood scarf's in plywood of less than, say, 1/2" and
then only if it is 5 or 7 ply. Also, marine ply is much better suited for a
scarf joint because of the more uniform ply thickness and absence of voids.

My opinion and experience. FWIW.

Steve
s/v Good Intentions