We are building a house and are ready to insulate. Our friend who is a contractor will have a whole lot of r-30 they will be removing from a commercial building that we can have for free. We live in the valley in N.CA and it does get hot, but not very cold. These are my questions: 1. We need r-38 in the ceiling. We have a large attic that will stay unconditioned for now and need to insulate below this area. We have 12" trusses with with the entire floor of the attic sheeted. Can I double up the r-30 even though it will squish it and leave now space for a flow above the insulation? 2. We have 2x6 walls. Can we squish the r-30 into the walls? Thanks for any help at all. Kirk.