Spring Freeze-up

Warmer springtime weather and lengthening daylight should signal to the northerner that winter's troubles are over. But just when you think you have it made, the sewer or the well freezes up. If not unfair, this quirk of fate seems a bit illogical.

One easy way to understand why the pipes freeze up so late in the season is to think about coming in from the cold wearing heavy rubber boots. One's feet stay cold for many minutes, even if the booted feet are propped up near a hot stove. It takes a long time for the heat to penetrate the boots. Then one may suddenly realize that the boots have become very hot, and will feel hot for many minutes after they are taken away from the stove. This example shows that energy is not transferred instantaneously.

So it is with freezing soil in winter except that the transfer of heat energy is much slower than in the rubber boot. As the top soil layer freezes, it gives up heat that is carried away by the air. Heat given up by the freezing of the soil below must be conducted away through the soil, a slower process. The level of freezing in soil can move downward as fast as three feet (1 meter) per month in water-saturated gravel cleared of moss and snow. However, in ground that is snow covered or which has a high humus content, the freezing will proceed downward more slowly.

Hopefully, the buried water pipes and the sewer are below the level of deepest annual freezing. If not, they usually will freeze long after the coldest weather. In extreme cases, the freeze-up might even come in early summer.