Stories from the NFCCA Newsletter, the “Northwood News”

Northwood News ♦ February 2011

Cold of Winter Reveals Where Insulation is Lacking

By Jacquie Bokow

It’s winter now, and the frigid temperatures and snow (even if in less copious amounts than last winter) can give you some insight into whether your home is poorly insulated, even without a formal energy audit.

Icicles are caused from heat loss, as heat from the living space gets into the attic and warms the roof.  Snow closest to the roof melts and the water drips down until it reaches an area of the roof that is below freezing, usually at the gutters or the overhanging eaves, where it refreezes as ice.

Icicles hanging from the eaves indicate heat is escaping into the attic, enough to melt the snow.  Low temperatures mean the snowmelt freezes again once it leaves the warmer roof.

Some people think icicles are decorative (think of those Christmas lights intended to mimic icicles), but the downside is that they damage property by degrading the roof prematurely.  Water may leak into the attic and house (which can rot wood) and gutters can come off the home under the weight of the ice.

Modern practice is to keep the roof cold, nearly the same temperature as outdoors, to minimize what is happening on the roof.  This is done with soffit and ridge vents, which allow cold air to flow under the roof sheathing and keep it cold.  But the solution could be a straightforward as adding insulation.

Side-by-side houses show the value of attic insulation.  The unmelted snow on the house at left shows it is well insulated.  The house at right has insufficient insulation in the attic so heat escapes and melts the snow much more quickly.

When we removed our old insulation (in preparation for new), we could not keep the house warm.  The heat stayed on almost continuously.  Attic insulation really makes a difference in your heating bills.

If you do notice icicles or snow melting on your roof even though the temperatures are below freezing, you would benefit from a whole-house energy audit.  A professional can pinpoint problems specific to your home and rate which ones should be done first to save the most energy.   ■

   © 2011 NFCCA  [Source:]