Posted by Linda Lockwood, Statewide FC Inspection Service on February 23, 1999 at 21:23:13:
In Reply to: Vinyl floor underlayment posted by Ron Carter on February 19, 1999 at 12:03:17:
As you know, vinyl floors are expensive, so I wouldn't recommend going with an underlay other than what is recommended by the mfg of the vinyl. Contact the company for recommendations. Most have an 800# and a technical dept., sometimes their recommendations are in the installers installation handbooks.
I don't know about Fiberboard, but I'd recommend 1/4" finished plywood over lauan.