Thanks for requesting me.
I know of one small theatre stage that used roofing felt under their final wood stage, on top of a plywood subfloor. They liked the feel of the stage floor once it was finished. There was little likelihood of water soaking into the roofing felt, so that wasn't an issue.
Another person's advice says this about roofing felt over wood and under a floor:
"...Can I install flooring over the concrete floor in my basement?
Basement floors are notorious for becoming damp, and moisture will ruin a floor unless necessary precautions are taken. But once these are done, you can put down many types of flooring, including vinyl, ceramic tile, engineered hardwoods, laminates, or carpet. Flooring experts generally recommend against installing traditional strip or plank hardwoods below grade. Engineered or laminate flooring is a better choice in this case.
* Woods: The ideal way to put down a wood floor over concrete that is subject to dampness is to first put down pressure 2-by-4 inch "sleepers," or lengths of wood, on the floor that are spaced 16 inches apart on center. Cover the sleepers with 6-millimeter plastic and then lay down 5/8-inch plywood. **** Cover the plywood with 15-pound roofing felt, and then install the engineered or laminate floor. **** Engineered wood floors may be nailed or glued to the plywood subfloor. Laminate floors, which may be tongue and groove or snap-together, are "floating" floors and not attached to the subfloor. If the concrete subfloor is always dry, however, engineered and laminate floors can be placed directly on the slab.
* Carpet: Carpet can be laid in the same manner.
* Vinyl tile: For vinyl tile, skip the 15-pound felt and apply mastic directly to the plywood.
* Ceramic tile: For ceramic tile, nail cement boards to the..."
[I added the "****" to show the specific location where your question is specifically addressed)
I would add some cautionary notes, though.
The roofing felt has to be placed almost perfectly, uniformly flat, and kept flat during installation of the laminate. This is because it will "give" over time, and then the surface of the laminate will "give" as well, leaving high spots where differential wear will occur.
If water gets under your laminate once the installation is complete, especially around the edges, the roofing felt may swell a little where damp, hold the moisture, "squish" if you walk on it... even if you don't get mold you could get "differential squishing" leading again to high spots. Be sure to fully cover your areas and seal to prevent water soaking in from the top. Water can be "wicked" in by wood trim so don't leave any standing water on the floors.
But if it works in damp basements, with those precautions it will work as well in your manufactured home.