I need a spacer betwen a wood deck and a long, wide horizontal steel plate. It’s outdoors (a bridge). Previously, the wood deck sat directly on the steel plate, collected water, and rotted out, making the steel scale very badly.

So I want a spacer material that won’t absorb water, about 1-1/4″ thick give or take.

I’ve looked at Trex, but my understanding is it’s basically wood chips glued together with plastic. Eventually water is going to get into that, I figure?

Is there any material that I can find at a lumberyard that won’t absorb water? It needs to carry the weight of vehicles, so it needs to not compress. For instance corrugated plastic roofing won’t work…
The bridge has a steel beam that’s flat on top and about a foot wide. The old deck was treated wood and water collected and sat on this steel beam, soaked into the wood, and made both wood and steel deteriorate.

So I want something that doesn’t hold water, you know, like plastic.

Global warming has been in the headlines lately and i have a question. Why is global warming being pinned on people and cars, power plants etc. When global warming trigures an ice age. If thats the case weve already had several ice ages. so couldnt global warming just be a cycle. Cus honestly unless a trex was driving around in a himmer wouldnt an ice age just be a earth cycle?