Other than possibly sound deadening I don't know it's purpose. My 38 has it as well. I left most of it but removed what had failed or interfered with what we were doing. Hopefully someone will know it's exact purpose and educate us both.

I believe that the bottom layer of carpet underlay had two functions. It helped water proof the floor by catching drips, etc (like from wet shoes, snowy boots) and containing them so it retarded rusting of the floor pans. That allowed the other underlayment and carpet to wick up the water and dry the floors. The other is to keep the carpet in place and resist it moving or bunching up.

@tiny @robert-keck Hey guys, Isn't that stuff pretty much like a thicker version of tar paper or "roof felt" ? I think it acted as bit of sound deadener in some locations like on the inside of door skins and roofs.

 

Mike

Posted by: @35mike

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@tiny @robert-keck Hey guys, Isn't that stuff pretty much like a thicker version of tar paper or "roof felt" ? I think it acted as bit of sound deadener in some locations like on the inside of door skins and roofs.

 

Mike

That's exactly what it is, a close cousin to tar paper.

 

I forgot to mention it has a circle with a capital A stamped in it ever so often. It appears to be die cut to fit over areas like the dimmer switch.

thanks for the replies!