I am starting a flood restoration project on a mobile home at the eastern shore in Maryland. I will need to remove a 12′ x 12′ section of the particle board subfloor that is severly damaged and black with mold. The insulation and the belly wrap will need to be replaced in this same area as well due to mold on the insulation. 

The insulation is an unfaced fiberglass batt isulation. The insulation is installed undernieth the floor joist with the insulation being held to the under side of the floor joist by the belly wrap (Vapor barrier). In stick built homes the vapor barrier for the insulation is installed on the interior side of the insulation. 

I have been told there are several reasons the vapor barrier is installed below the insulation on mobile homes. The vapor barrier is intended to keep insects and rodents from nesting in the fiberglass insulation. The crawl spaces are usually damp and if the insulation was exposed to the damp crawl space the insulation would constantly be wet. and ineffective

I was told by a salesman for a mobile home part supplier that I should use an R-30 kraft faced paper insulation with the kraft vapor barrier facing the interior of the house as well as the belly wrap vapor barrier on the underside of the insulation. Is this correct? Can you have a vapor barrier on both sides of the insulation? Also can anyone recomend a good online supplier for mobile home parts? This is an out of town project for me and I have not located any mobile home suppliers close to my peoject,

Thanks Paul