I am thinking of installing vinyl siding on my home. I have several questions. The first question is should I put foam board insulation underneath ? I heard from one of the contractors that this my cause a moisture problem in my home. The second question, what grade should I put up .045 .050 ? Is one better than the other and is there a big difference ? Lastly, what manufacturer of vinyl siding makes the best product ? One contractor told me some manufacturers mix in recycled product with the pure product. I'm confused PLease Help !