Can I install Trex over Duradek?

by Gary
(Alberta, Canada)

Hi,

My deck extends off the second level and is covered with Duradek. I'd like to install a composite like Trex because the Duradek is weathered and I've never liked it.


The Duradek is laid on plywood and the plywood is laid on joists. The underside of the deck is the ceiling of the porch below. That ceiling has a few pot lights in it, and metal soffit material with lots of perforations.

The Trex will not be a water seal to protect the joists, pot lights, wiring and soffits underneath. So would it be best to just leave the Duradek on and install Trex right on top of the Duradek? I'm worried that the screws that hold the clips and Trex in place might allow water to get through the Duradek and wreck everything beneath.

Thanks for your help!