What Insulation To Use In Bathroom Walls. Solid floors of brick, tile or stone were frequently laid directly on to soil, sometimes. A vapor barrier (the simplest one being some plastic sheeting) is simply added on top of the insulation material and tightened to the construction by using a staple gun.
I would use some 2 rigid foam board on the face of the studs, if enough clearances for other bathroom fixtures, then add d.p.
Small bath fans provide adequate bathroom ventilation for 79 sq.ft. Insulation in your walls is not only energy efficient, it also reduces noise. Cut pieces of a 2 foot x 4 foot board to fit between the joists, blocking off the fan from the insulation. Our bathroom has tiles matching the floor on the walls, but the vanity cupboard, which is particle board, has a thin brushed aluminium outer layer on to keep it.