1980 Itasca Seahawk Fiberglass Construction

[rajoford]

Looking at the sales literature for the Itasca Seahawk it shows the wall construction. A 1/16" layer of fiberglass. Structural substrate then another 1/16" layer of fiberglass and finally the 16 gauge steel channel. Good strong construction.  OK Does anyone know what the 'structural substrate' is?

thanks
Bill.

[DaveVA78Chieftain]

High Density Foamcore

http://thefoursimplequestions.com/built.php#walls

Dave