Cold Bridges and Moisture—The Everlasting Enemies of Overland Builds

If there’s one thing every full time van / truck dweller knows, it’s that moisture is the enemy. Moisture can come from a variety of sources, but when it comes to overland builds, the biggest culprit is cold bridges. Cold bridges are areas where two different materials meet and create an area of low temperature which can attract moisture. . So how do you protect against cold bridges and avoid mould in your build? Let’s explore.

What Are Cold Bridges?

Cold bridges are created when the cold is able to bridge from the outside of the truck to the inside and creates an area with a lower temperature than its surrounding environment. These areas tend to attract water vapor, which then condenses on the surface and leads to mold issues. To prevent this from happening, you need to make sure that no metal surfaces exposed to the outside are bridging to the inside and touch any wooden surfaces in your build. This can be tricky because most overland vehicles have metal frames that provide structural support for their walls and cupboards. Even metal within the walls covered in ply can cause damp and mould in the right environment. These issues are most obvious when living full time in cold maritime environments.

To protect against these metal-wooden connections, you need to use insulation material such as foam or fiberglass. This will act as a barrier between the two materials. Additionally, it's important to ensure that all cupboards have adequate circulation so that air is able to move freely throughout the space without creating any “dead zones” where moisture could accumulate.

Photo of Overland truck aluminium window in Central Asian winter. Outside temperature -20°c or below. Inside Temperature above 20°c.

Finally, if you're using any kind of plastic material in your build (such as PVC piping), make sure that there is enough ventilation around the pipe so that it stays dry and doesn't become an attractive site for mold growth. Additionally, try to avoid using plastic pipes near windows or other sources of water since these can quickly become breeding grounds for dampness and mould growth if not properly ventilated. Even Melamine faced interior ply can become a damp problem when it's not allowed to breath.

Cold bridges are one of the biggest causes of mould problems in an overland build due to their ability to attract moisture from their surroundings. Even the big million euro plus overland truck builders struggle with these issues. However, by understanding what causes cold bridges and taking steps to eliminate them (such as using insulation between wooden structures and metal frames) you can help keep your overland vehicle free from dampness and mould growth—even in the coldest climates! Air circulation is also important. In my new build I am using 12v computer fans in problem areas to ensure proper circulation. So if you’re looking for ways to keep your build healthy during long trips across the country or globe, consider investing some time into eliminating cold bridges today!