Preventing Ice Dams
  1. "R" value refers to a materials rate of heat loss per hour per square inch of thickness. You want the highest R-value possible in your floors, walls and ceilings.

  2. Minnesota Building Code dictates that you need a minimum of R-49 in your attic. That equates roughly to 13" of fiberglass or 15" of cellulose or 7" of sprayed foam insulation.

  3. If you can see a lot of light through your eaves you have half of your attic ventilation addressed. The other half is the ventilation up near the peak of the roof either in the form of box vents mounted to the roof deck or an open ridge vent along the majority of the ridge.

  4. This is blown fiberglass insulation. It has an R-value of about 3.9 per inch of thickness.

  5. Softwoods have an R-value of about 1.3 per Inch.