How and why do buildings expand and constrict?


Not sure what category this falls under but I’m curious. My bad if my flair is way off.

In: 1

Temperature changes can expand and retract the moisture retained in some building materials, particularly untreated wood.

All materials change size with temperature, as their molecules’ vibrating more or less changes how tightly packed they can be.

Wood and other materials (but in buildings mostly wood) change size with the moisture content of the air. More moist air causes them to absorb more water and expand to hold it.

It depends on scale, I believe. Buildings like tall skyscrapers have specific mechanisms to be able to endure or say through earthquakes, high winds, or other natural disasters, some of which involve flexible parts or fun physics.

If you’re talking about when a normal house creaks or pops, that’s just from heat/cold causing the frame to expand or contract. Heat causes material of any kind to expand or contract, but it’s usually not noticeable. On the scale of a house, this can become an inch or a few centimeters which is enough to build up stress that, when released, result in the sounds we hear.

Physics is fine. Buildings expand due to their materials heating and cooling. This is factored in during construction and often requires expansion spacing, if you ever see brick work of a certain length you’ll see a space periodically. In steel work you’ll see members on roller joints to compensate for expansion also. There’s plenty more examples in construction. The basics of the physics is as the molecules heat up, the get excited, move more, thus occupy a larger space. When cooled, they move less, occupy a smaller space

Thank you everybody! Much appreciated.