Insulation, Radiant and Vapor Barriers - vapor barrier

Hi, My son wants to insulate my hundred year old kitchen. He has removed the plaster and lath strips. Does he put the vapor barrier up before or after the insulation. Also what # insulation should he use. Thanks, Anita

the barrier goes after the insulation.on the inside just before the drywall
Compressing thick fiber glass blanket insulation into a smaller wall space will not necessarily increase your insulation's efficiency. Fiber glass insulation works on the principle of trapped air pockets. By compressing fiber glass insulation, you decrease the amount of air trapped in the material. R-15 fiber glass insulation is designed to provide better performance in 2 x 4 walls. R-21 fiber glass insulation works best in 2 x 6 new wall constructions.
just a quick note -the yellow kind is less picky than the pink
rt

I think from up there to down here. His R-15 for 2X4 would be our R -13 and his R -21 for 2 X 6 would be our R-19.We use a 2mil poly for a V/B over the insulation after its all in on the room side ;) ED