I'm building a deck (1st time building a deck) using cement deck blocks for
support (21 blocks). Deck is 10' x 12' on the side of a AG pool. Each joist
is supported by 3 - 4"x4"s set in the deck blocks. Eack 4"x4" has to be cut
to fit due to uneven ground.

I have 4 joists in place now and I notice they arent perfectly even with
each other. I was using a 2' level to set the hight as I was putting them
in. When I stretch a string across all the joists I can see a variation of
up to .125" from joist to joist. I could go back and shim under some of the
joist but I was wondering how much differance it will make?

Will this variation be noticable when the 5/4 PT decking is screwed down??

Also, Do you have to screw the decking down at every joist? Can you screw
down the decking at every other joist then alternate with the next board??

Thanks for any advice!

Steve