Hardi™ is a fibre-cement product and the LP product is a chip-board/resin composite. The Hardi™ comes both finished and unfinished, the LP is unfinished and must be painted with a high quality exterio ... read more
Make sure that your attic is properly insulated. Make sure the seals around all windows and doors are in good shape. If you can see daylight air is entering and leaving as well.