Why does Wood Pop?
Wood popping can be a phenomenon often heard but rarely understood. Here we’ll explore some of the underlying causes that make wood “pop”.
Shrinking and Expanding
Wood is made up of cells that contain water, and these cells expand when they absorb moisture and contract when they give off moisture. When wood is exposed to variable levels of heat, humidity, or dryness, it has the tendency to expand and contract, causing wood to “pop”.
Residual Stress
Wood “popping” can also be caused by the residual stress left over from the cutting, drying, or shaping of the wood. This residual stress is released when the wood is exposed to changes in temperature, air pressure or humidity, causing it to crack and makes popping noises.
Reaction Wood
Another possible cause of wood popping is reaction wood. This is formed when a tree is bent due to something like wind, snow or excess weight. This type of wood is much more compressed than normal wood and again, when the environmental conditions cause the wood to expand, it can cause popping sounds.
Tips to Avoid Wood Popping
There are some things that you can do to reduce the frequency of wood “popping”:
- Use wood that is dried and seasoned properly
- Choose wood with consistent grain patterns to help with equal wood expansion
- Keep wood materials away from moisture or high temperatures
- Use glue, nails, or screws to secure wood pieces to reducing tension
Whilst wood popping can be an annoyance, the reality is that it is quite normal and can not be completely avoided. The above tips may, however, help reduce the potential for wood popping in certain situations.
1. What specific conditions cause wood to “pop”?
Wood “pops” when moisture from the environment accumulates in the wood unequal amounts in different sections. When the wood dries, this causes the wood to shrink, creating small gaps which “pop” when pressure is added. This problem is more likely to occur in wood that has wide grain, such as red oak, due to the large amount of air in the grain.
2. How can wood be prevented from “popping”?
To prevent wood from “popping”, you should use spacers when you apply the glue, pre-drill holes when fastening screws, and use a good quality sealer. Additionally, you should maintain a relative humidity level of around 45%, and use wood with an appropriate moisture content for your climate.
3. How is the popping sound created in wood?
The popping sound created in wood is caused by trapped air bubbles, moisture, or other gas that is released from the wood as pressure is applied. This is typically caused by wood shrinking or expanding, friction between wood pieces, or the breaking of chemical bonds due to oxidation. Pressure, temperature, and humidity can all influence how strongly the popping sound is expressed.
5. What implications does “popping” have for the durability of the wood?
Popping can reduce wood’s durability. When wood experiences popping, a portion of the wood splits. This split reduces the wood’s structural strength and makes it more susceptible to cracking and warping. Popping can also create loose particles of wood fiber, which can weaken it further. The more popping that occurs in a piece of wood, the less durable it will be in the long term.