I have been reading your solid wall insulation posts with interest. Why does nobody EVER mention cork? Cork is a natural material that breathes(?), is inexpensive, easy to apply and above all for a very small house, narrow in width. To me it seems the obvious material. So what do you people think? I would be grateful for your opinions.
Cork is 90% air and as such compares very well with the best products available, polystyrene and Styrofoam are both 98% air and 2% plastic.
Cork is also waterproof, that puts it well in front of all open cell insulation's, especially compared to fibreglass that get wet, forms internal ice patches and becomes totally useless.