John Caughey said:
Be careful if you follow familygardens’ advice on trex… I wasted a year and too much $ making it into a ladder.
Some have found plastic trim boards that won’t fall apart and crumble, to be beter than using Trex or trex knock offs.
John
Trex and other similar products have an unpleasant habit of sagging between verticle supports, unless the supports are less than 18 inches apart. They are not designed for that use.
One rule of thumb that has seemed to be a good one, is that for the same dimensions, synthetic lumber can only span half the distance unsupported as compared to wood, and even then expect slightly more sag than real wood.
Greg
Craig-
In regards to what Dirk used, are you talking about what he put on top of the PVC pipe then the track on top of that? I think he called it Hardy Board. Something like a cement house siding material if memory serves right.