Moisture Problems: An Unseen Hurdle of Wood Transportation

It’s easier than you think for unwanted moisture to work its way into a shipping container and cause problems with your load of wood.

Effective moisture management, however, can prevent those problems. An environmental data logger allows you to be proactive by continually monitoring ambient temperatures and humidity. And if damage were to occur, you would have the information to track how it happened.

We’ll explore all of this in the following areas:

• Moisture’s impact on transported wood
• Methods for preventing moisture problems while shipping wood
• The best way to monitor moisture while transporting wood

We’ll begin with how moisture affects wood during transportation.

Moisture’s Impact on Transported Wood

If not sealed properly, shipping containers often end up with moisture inside. And if not properly managed, the moisture can cause a lot of problems for wood. This includes issues like mildew, mold, and warping (think twisting, bowing, or cupping).

Another problem that can arise is a phenomenon called container rain. This is when moisture in the air inside the container condenses on the cooler ceiling and walls and drips onto the cargo like rain.

Cargo sweat is similar, except the condensation forms on the cargo itself, like droplets on the outside of a cold glass of water. It happens when the cargo is colder than the dew point of the air around it.

Even if the wood has been dried to an appropriate moisture content previously, it can still develop moisture-related problems during shipping.

Moisture works its way into the shipping containers in a couple ways:

• Moisture can seep into the shipping containers from the outside. Shipping containers are sometimes waterproof but not always airproof. Water vapor can penetrate where water droplets can’t, wreaking havoc inside the containers.
• Any interior wooden components of the shipping containers themselves may have a higher moisture content than the wood being shipped. The moisture will move to the wood with the lower moisture content (the wood being shipped) and cause problems if the wrapping around the wood isn’t sealed. Also, the wood pallets the lumber sits on could be green, which can release a lot of moisture into the air.

So, how do shipping companies prevent moisture problems?

Methods for Preventing Moisture Problems While Shipping Wood

Because of the frequent moisture problems associated with shipping, shippers have developed a few methods for keeping moisture in check. We feel the best of these methods is moisture monitoring.

We’re going to talk about this and other methods, but we’ll start with an initial preventative measure: kiln drying the wood.

Kiln drying

Kiln drying involves drying wood in a kiln down to a specific moisture content, usually to certain percentages below 20%, depending on the future use. (If the wood ships on pallets or with crates or dunnage, the international ISPM 15 standard requires the wood packaging to be heat-treated or fumigated.)

Many people think that once wood has been kiln-dried, it will always be ready to use.

Unfortunately, this is not always the case. No matter how much a piece of wood is dried, it will always gain or release moisture as the humidity around it changes. This includes changes that might happen during transportation.

Wrapping the wood

As we’ve already hinted at, a good way to prevent outside air from harming a shipment of lumber is to wrap the lumber. Usually, this is done with a plastic vapor barrier, which acts as a wall against invading moisture, whether it’s seeping into the container or coming from green pallets.

Shrink wrap can do the same, but it can tear if it’s bumped or scraped against something else.

Now, let’s look at our favorite method.

Moisture monitoring

Continuous monitoring is one of the best ways to know what’s happening to wood moisture during transportation.

Before loading the wood to be shipped, use a wood moisture meter to measure its moisture content. Check it against the moisture content your customer or the product’s end use requires. Kiln-dried lumber is generally 19% or less, and wood for interior products is often dried lower. Readings above the target can mean the wood wasn’t dried properly.

At the end of the shipment, have the receiving person measure the moisture levels again and compare them to the levels taken at the beginning of the trip.

If they are higher, you’ll know more moisture seeped in somehow. If they are lower, you’ll know moisture got out. If you see any significant changes, you will know that future shipments may need additional moisture controls.

Aside from using a moisture meter to check the wood, we also recommend monitoring the temperature and humidity of the shipping container itself.

That’s where monitoring technology comes in.

The Best Way to Monitor Moisture While Transporting Wood

One of the best ways to monitor temperature and humidity throughout the transportation of wood is through something that can take regular automated measurements. And our Smart Logger™ V2 does that very thing.

The Smart Logger is an affordable data logger. All you have to do is set it in the shipping container. It will discreetly log the temperature and relative humidity of the container, taking readings as often as you set it to.

It’s useful for getting an accurate picture of how the humidity and temperature changes affected your wood, particularly if you sustained significant damage on recent shipments.

Smart Logger’s Bluetooth® capabilities allow you to receive all the data on your smartphone when you’re within range. And even if you’re out of range, the Smart Logger will continue to monitor conditions, which the person at the receiving end can later view as a report.

The Smart Logger pairs with a mobile app that allows you to monitor relative humidity and temperature during transportation whenever the mobile device is within Bluetooth range.

If your load sustains damage during shipping, the Smart Logger can help you sort out what happened. You can check the recorded data against weather conditions during the trip and shipping logs to find the cause and piece together the story behind the damage.

Then in the future, you can change your techniques to help prevent such disasters.

Without a data logger, you may have no idea when things went wrong and what caused the problem. But the data in the Smart Logger gives you the pieces to help you solve that mystery.

Optimal Moisture Management with Wagner Meters

The journey of wood transportation requires plenty of planning beforehand. After all, you’re dealing with Mother Nature, who has an uncontrollable mind of her own!

That means changes in temperature and humidity are unpredictable and difficult to control.

A number of different solutions are available with varying degrees of success. Solutions like making sure that the shipping pallets and the wood being shipped are properly dried. And keeping the wood wrapped as a further barrier against moisture.

However, continuously monitoring moisture conditions with the Smart Logger can help you keep close tabs on what’s happening to your load of wood. If moisture damage occurs, you can connect the dots between time, humidity, and temperature.

And if both the shipping and receiving parties have the Orion® 950 to measure the wood’s moisture content before and after shipping, you’ve got an excellent force for moisture management during transportation.

How could these tools help your next shipment?

Check out our Smart Logger and Orion 950 before your next transport!

Shop Smart Logger Shop Orion Moisture Meters

Last updated on October 22nd, 2026