Thanks for your answer. We are using sheating not aluminum and the studs on the exterior walls are 2x4. We live in so. cal so it stays pretty warm. I think the r-11 will do just fine.

We will be using a barrier for sure. The mold and water damamge that is there currently are a result of no barrier before. What is the best insulation to use?

We just bought an 87 mobile home and we are completely renovating the entire home. What is the best type of insulation to use on the exterior walls? Should we insulate the interior walls?