Anyone working with wood – builders, carpenters, floor installers and others – needs to make sure the wood has the right moisture content before using it.
Wood that is too wet will shrink as it dries, causing warping and splitting of the final product. The shrinkage is even more consequential when it comes to buildings.
Wood that is used in external walls and support structures needs to reach a strict moisture content range. Even a couple percentages higher than the recommended maximum compromises the strength and longevity of the entire building.
The easiest and quickest way to check moisture content of wood is using a moisture meter, either the pin or pinless type. But how to check moisture content of wood without meter?
If you don’t have a moisture meter or don’t want to use one, there’s only one other way to measure moisture content. Unfortunately, it’s a bit tedious.
The Oven Dry Method
Oven drying is the most accurate way to measure moisture content in wood. It’s more precise than moisture meters.
The only problem with it is that it takes time and requires a purpose built kiln or oven that most people don’t have at home.
In the oven dry method you measure the weight of wood then dry it in an oven set at 103C. You regularly remove the wood and weigh it. When the weight of wood no longer changes, it’s dry.
Now, you can use the final weight of the wood and the original weight to determine the moisture content. That’s easy because the lost weight is water.
The slowness and tediousness of oven drying is why it’s rarely used today even among professionals. Only in situations where extremely precise moisture content measurements are required is oven drying used.
Otherwise, a moisture meter is perfectly fine for most applications.
Can You Dry Wood in a Kitchen Oven
If you want to measure the moisture content of small pieces of wood, you can use your kitchen oven. Just keep in mind that it may affect the quality and structure of the wood. That’s why woodworkers use speciality built kilns to dry wood.
Measure the weight of the wood pieces before putting them in the oven and record the original weight. Arrange two racks in the oven, one at the top and one at the bottom, and place an oven thermometer inside.
Set the oven temperature dial to about 103C. Once the oven thermometer indicates this temperature, arrange the wood pieces inside, making sure they are not in contact.
Leave the wood to dry for an hour. If your oven has a fan setting, turn it on. Moving air dries the wood faster and evenly.
After an hour, remove the pieces of wood with gloves and measure their weight. Record it.
Return the wood and weigh them every 15 minutes until the weight stops dropping. Use the final weight to calculate moisture content. Take away the final weight from the initial weight. Divide this difference (which is the weight of water) by the final weight and multiply by 100.