Slider help...
 

What do you use for the top of a funbox.....

trex......or pvc sheets.

HDPE. Something thin is all you need, like 1/8-1/4", if there is a plywood base. If there is no plywood base you should use like 1/2"

This

also make sure all your wood is PT. otherwise youre wasting money cause your shizzzzz is going to rot fast

i have 1/2" 3x7 white poly pro sheet that seems to work great.

www.RailWerx.com/armorgrind

Check out this stuff, I am building my slider with this HDPE/ALuminum

This is an aluminum backed plastic. You screw down the aluminum, then slide on the plastic over the top of the screws.

anything plastic under 1/2inch thick will bubble in between srews once layed out in the sun.. I would recommend using 3/4-1 inch thick if you can afford it, and Treated Wood is a must for long term hits!

CH