Cold upsetting our houses, too
So, did you notice last week when we had one overnight temperature of minus 8 and the next night of minus 11 that your house seemed a tad angry? That it made loud banging sounds as if to say, “For the love of whatever, warm me the heck up!”
Well, here’s why: This is from the Carlton University of Canada’s monthly magazine:
“In extreme cold weather conditions we can learn rudimentary lessons in physics. Materials that make up our buildings change with their environment. In the winter, all exposed materials will slowly shrink as the temperature falls. In addition, fibrous or porous materials, such as wood, will also give up moisture to the surrounding dry winter air, accentuating their shrinking or contraction. In the spring, as the environment warms and the air gains moisture, wood will gradually swell and expand to its “normal” size and proportions.
“The extreme and rapid shift from unseasonably warm temperatures (+/- 0° C) from one day, to deep-freeze temperatures (- 36° C) the next, causes a rapid shrinking in all exposed building materials. In addition, buildings are designed in such a way that many of its parts are exposed to warm environments (on the inside) and at the same time to cold environments (on the outside).
“Roofs and walls are both good examples of this. Wooden studs that make-up walls have one face close to the outside and one face close to the inside, usually with insulation in between. Roofs have a more complex structure built from rafters or wooden trusses shaped in the form of a triangle. The top parts are exposed to near-outdoor temperatures (the temperature of the vented attic space) and the bottom part is wrapped in insulation near the ceiling of the warm living space below. Parts of the structure therefore, are shrinking while others are staying essentially the same. The differential temperatures cause the wall or roof assemblies to distort in shape. In principle, these systems (walls and roofs) are designed and built so they stay in place and are connected to each other in a sturdy and relatively tight manner.
“While the connectors that provide this structural assembly vary (nails, screws, metal plates, etc.), they are designed to resist excessive movement while allowing for some expansion and contraction of the component parts.
“When components of a building shrink quickly, an extreme amount of stress is produced in the connections and joints. Excessive pressure may lead to a slipping of the members within this joint. When stresses are released quickly, a loud popping sound can be heard as one member moves against or away from another (or from the connectors).”
So, first of all, you weren’t going crazy, you weren’t hearing sounds that weren’t there. Second, no one was throwing snowballs at your house at 3 a.m. And, third, your house wasn’t actually angry. Not this time, anyway.
Your house, like you, like the rest of us, just had Them Old Cold Weather Blues (in D minor).
Now of course that doesn’t mean it wasn’t frightening and it doesn’t mean that we shouldn’t have our houses checked out to make sure nothing significant shifted in a significant way, but at least now we know what we’re dealing with.
Okay, not really, but when you think about it, while the scientific explanation is interesting and reassuring, poltergeists would be a lot more fun.