R-value

Myth #6:  Six Inches of fiberglass equals R-19 and pretty good for Maine.

Truth:  NOT!!!  Effective R-value of this type wall is actually R-12 or lower.

Wood framing every 16 inches (R-value = 5), represents 20% of the area of the wall and lowers the overall R-value.  Added to that, fiberglass insulation is not a good air infiltration barrier (leaky!) and you have a pretty poor insulation method for Maine

Goals for New Construction:  We recommend an effective R-40 minimum walls with no thermal breaks and very tight.  For Deep Energy Retrofits, we recommend a minimum of R-30.

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