When stone walls have deteriorated on the outside, water can penetrate and sit in all of the various nooks and crannies. Come winter time when the ground freezes, the water in the wall freezes as well. When this happens, the ice can literally lift the stones in the wall above it, causing what we call Frost Heave. When water freezes, it expands about 2 fold. When soild freezes, it can expand up to 10x’s, depending on soil type. Frost heave usually shows itself in the form of cracks in ceilings and walls, stuck doors and windows, and uneven floors.