1.   And, it causes ice dams on a few unfortunate abodes.

2.   And no matter how well it and the ducts are insulated, that furnace will make the attic warm, which can cause ice dams in winter.

3.   A house with a warm attic has a warm roof, and it is this warm roof that causes ice dams.

4.   Heavy rain last Thursday flooded homes and caused a dam near Lynchburg to collapse.