Rot Proof Decking for Garage Inspection Pit

[aesmith]

Hi,
Our garage has a concrete floor and concrete inspection pit. Currently the pity is covered with wooden slats of around 2" thick but varying in both thickness and width. They're pretty rotten and I've replaced a couple. I've found that a sheet of 3/4" plywood over the top gives a level surface just about flush with the main floor, and also reduced the risk if one of the slats were to break or shift.
The trouble is that covering with plywood now means that the pit and the covering is even more damp so this isn't a long term solution.

Does anyone have any suggestions for something rot-proof that could be used instead? The covered area is around 44" by 66", so the slats (or their replacements) need to be strong enough to span that. It doesn't need to bear the weight of a car, but I do sometimes move my motorcycle in there.

Thanks in advance, Tony S

 

[foxhole]

You could use plastic decking board over a steel frame.
I used electrical conduit tray cut to width and welded in small sections . Strong and lightweight to lift when access required.
https://www.electricaldirect.co.uk/...MIprqR8LXm4QIVy7vtCh1GHgeFEAQYBCABEgJv-vD_BwE

 

[scbk]

Softwood treated with preservative or larch, should last a few decades

6x2s or whatever you can get locally

 

[jj4091]

https://www.gemco.co.uk/product/gemco-pit-covers/

 

[lostinthelight]

Try leaving an inch gap between boards ,it helps moisture escape which keeps underside dry on mine.

 

[aesmith]

Thanks everyone. I was looking into recycled plastic boards, but I don't think they'd be strong enough for a 44" span as they're intended for decking. Easy answer in the short term would be to replace the existing slats with pressure treated. The actual thickness needs to be greater than 2" to be flush with the concrete floor, but I could work around that by fitting something into the recess to get the height exact. I think what's made the dampness worse was putting down a plastic sheet to catch drips when I've been working on the motorcycle. I probably shouldn't leave that down all the time.

I don't think I could live with gaps between the slats, I'd be for ever dropping things down between them and also I think they'd be more prone to shift.