Vannin' Home Forums Chevy General Discussion Cockpit Flooring Advice Wanted

So I just pulled out the flooring in my 85 gmc vandura. The tub looks great, no rust! But the firewall material under the rubber is nasty, wet, and falling apart. Any tried and true methods for replacing that? What material should I use? Any suggestions for replacing the old rubber floor mat that lays over the fire break material?

First, I'd find out why it is wet and where it is coming from before I put anything in or dry it out.

+1 on chase down the moisture and fix that problem. Could be any number of issues causing that. Bad windshield gasket is common, leaking heater core is common, even door seals. Until you fix that problem, it doesn't matter what you put down, everything will hold the moisture against the floor and rust will follow soon.

Once it's fixed, just plain old carpet underlayment that most of the auto carpet sources sell. Killmat or Dynamat are the two sound deadeners that seem preferred by car audio installers if you're going that route. The sky is the limit, but it all depends on what you want to use the van for in the end and a lot of personal preferences.

Carpet Link

The water is just moisture from 40 years of people getting in and out. There isn’t a lot of opportunity to dry out up here between 6 months of below freezing/snowy feet and damp summers. Add the moisture from people since it’s a class b rv. The padding was just soggy and the tub was damp no leaks or anything.

Thanks for that carpet link, unfortunately they want almost $400 to ship a 6’x3’ carpet chunk up to Alaska. Just ridiculous.

You can always try a carpet remnant from a home carpet store. Most auto parts stores also sell generic carpet by the roll as well.

I'm planning on doing a mix in mine. Sound deadener first Plywood base layer with vinyl plank flooring we have left over from the home renovation, possibly a shag rug or two.

There are hundreds of things you can go with, but it all boils down to personal preference and what you can get on the cheap up in the frozen tundra. I didn't realize what your location was earlier. Might want to look for something with a really good insulation rating.

just a quick mention, I see your damp problem was not by leakage.
I recall my pass side floor was very damp and horrible, I was a cats whisker away from pulling the dash to get at the heater box (`80 G10 Shorty) when I realised it was not coolant.
Over the years prior to me owning it , it had been leaking down the seal at the front of the pass door. I replaced all the door seals - job done - so pleased it wasn't the heater box. ha.