Bill wrote:
I measured and cut 1by8 into a 65" running board, using an antique
hand saw for posterity. I hammered three 7d (2 1/4") nails into each
end and when I nailed it to the roof joists, the roof joists in
between the ones on the ends were each 1/8" to 1/2" away from the
board. That could have worked out far worse, but I ended up using 6
nails instead of the 15 I had planned. It occurred to met that when
I nail staples into the board it may be wise support it from behind. I'm
having about as much fun as Lew could wish for me to have under
such warm circumstances! No one would want to be paying me by the
hour, I just came in to look something up...

Bill

Stick a couple of nails in every other joist - not just the ends. You won't
have to worry about a springy board then.

--

-Mike-