Finance and Business How do you insulate a tile wall? What is the best insulator for walls? The best insulation for walls when it comes to new build homes or remodels is going to be Nu-Wool, foam board, or open cell spray foam.Jul 1, 2020 Related Posts:Tips and tricks to easily...Diagnosing and repairing your Hayward AquaRite Salt System.IS can spray foam open or closed cell?What is the R-value per inch of spray foam?How to cut, shape, and glue EVA Foam - what is the best glue for it?