On Apr 25, 9:43*am, "Thomas G. Marshall"
. com wrote:
I've spoken to a number of people who have put composite decks in and they
followed the manufacturers suggestions carefully and ended up with boards
that just "seem" too far apart. *A friend of mine has these large gaps
around his posts that I'm not particularly fond of.

And two of these people say they've never seen the boards expand nor shrink
the way the manufacturer warned. *I'm not sure of the brands.

But this reminds me of something a construction guy told me once about PT (I
know, a different issue): "Don't ever listen to the advice about keeping the
boards a nail width apart....they will dry and shrink on their own". *The
only reason I mention this is because I would like to know to what degree
such rules of thumb (PT or composite) are real, or just passed along advice
that never really applies.

For example, has anyone seen trouble with compostite decking boards placed
flush (say, *in the summer)?

Thanks!

You need some gap , air venting of moist air. there is expansion, and
for you, dirt and rain removal . Also an ease of cleaning.