Moisture trapped inside a home’s walls can cause big problems.

It creates the perfect conditions for mold to grow, damages building materials, reduces energy efficiency, and can even harm human health by lowering air quality.

The key to preventing these issues is spotting moisture early before it leads to major damage.

Now, researchers at the Department of Energy’s Oak Ridge National Laboratory (ORNL) have developed a microwave radar system that can find and measure moisture inside walls without needing to remove drywall or cladding.

This non-invasive method makes it faster and easier to detect moisture problems before they get worse.

The team’s work was recently published in IEEE Xplore and presented at the IEEE Radar Conference 2024.

Microwave radar works by sending out signals that reflect off materials and return to the radar system.

These reflections can reveal details about the materials, such as their moisture content. Unlike visible light, microwaves can penetrate deeper, which makes them perfect for looking inside walls.

Most homes are built using wood frames, and wet wood is a breeding ground for mold. The researchers focused on detecting moisture in oriented strand board (OSB), a common material used in wall construction.

By analyzing how the radar signals bounce back from the wood and other layers in the wall, the system can measure moisture levels and even identify which parts of the wall are wet.

The ORNL team started by testing small pieces of OSB. They dried the wood in an oven, conditioned it to specific moisture levels, and then used the radar to measure the moisture content. The results matched the readings from traditional handheld moisture meters, with less than a 3% difference.

Next, the researchers added a layer of drywall in front of the wood to see if the radar could still detect moisture. The radar successfully measured the moisture in the wood through the drywall, proving it could work in real-world conditions.

The team then created a small, portable version of the microwave radar system for practical use. This version can scan walls, roofs, and even foundations to find hidden moisture. By using frequencies between 10 and 15 gigahertz, the system is lightweight, easy to set up, and adaptable for public use.

The researchers plan to expand their testing to include full wall assemblies with different materials like brick and vinyl siding. Their goal is to make the system affordable and widely available so homeowners and inspectors can use it to catch moisture problems early.

With this technology, small moisture issues can be fixed before they cause major damage, saving homeowners time, money, and stress. It could also help homebuyers identify hidden problems during inspections, offering peace of mind for their investment.

“We’ve created a system that’s portable, easy to use, and specifically designed for residential homes,” said ORNL’s Philip Boudreaux. “There’s still work to do, but this technology has the potential to make a big difference in how we detect and prevent moisture damage.”

With promising results so far, this innovative radar system could soon become a valuable tool for keeping homes safe, dry, and energy-efficient.

Source: Oak Ridge National Laboratory.