Insulate:The main cause of ice dams is an overly warm and moist attic so installing additional insulation is an easy solution

Ventilate:This will remove an excess heat as well as water vapors, which can condense in the attic and cause dry rot on wood

Removal:On very low-sloped or flat roofs, you may need to shovel off all the snow. On a roof with a greater pitch, removing three or four feet of snow above the roof line will prevent further ice build-up

Flash Properly:Roofs with difficult peaks and valley's should have proper flashing as well as proper underlayments such as ice and water shield, along the roof life as well as chimney area's and valleys.

Install right the first time:Call a roofer who knows what to do and if it is even within your budget consider a metal roof for low sloping roofs that require a minimum pitch. The asphalt may leak every time snow runs underneath it!