I'm having a professional build me my "last" chicken coop (hee, hee). I'm handling the interior finish out myself to save money, and also because I enjoy puttering around with chicken housing. I'm going to be insulating this coop, so I know I need to cover the insulation with something on the inside, but what? Ideally, the material will be easy to cut with a hand saw because that's all I have to work with. Any ideas?