How to re-insulate a wall under sink?

Larry, I don't want to see you make a big mess with that silly putty . Breaks my heart to see some one make a big mess they cant chisel their way out of . The foil is a moisture barrier and gives you some thing to staple down . If you can use GREEN BOARD . It wont rot. It's a com men sense project . Use green board , 1 1\2 Screws , tubed cal king white , mount the water valves in the com men area , Just relax , do the job , and have a drink when your done.Non alcohol if not of age.