Thermal bowing on a door

What is Thermal Bowing?


Thermal bowing is a temporary condition that can occur on exterior metal doors when the temperature is vastly different on one side, compared to the other. Thermal bowing will normally occur when one side of a door is too hot, but it can occur in reverse, under extremely cold conditions.  When there is a large temperature difference, the exposed surface of the door can swell/expand on the heated side, causing the door to bow. When the temperature has reduced and is no longer at an extreme difference, the bowed door will return to its normal form.

When a door bows it becomes difficult to latch and unlatch hardware, or open the door, due to clearance issues caused by one side of the door expanding, and the other side remaining in the normal state. Some factors that can increase the chance of bowing are the door color, the amount of sunlight exposure, and the type of core used inside the door. Darker colors soak up more heat, which intensifies the temperature differential and in turn, can cause the door to bow. Similarly, the density of the door’s core will also play a part in how much the door bows, or if it does at all. For example, heat cannot distribute evenly through a door with a polyurethane or polystyrene insulated core, which contributes to the temperature differential that causes bowing. A door with a honeycomb core is less likely to bow, due to the holes in the honeycomb core that allow heat to transfer.

Steps You Can Take to Help Alleviate the Chances of Bowing:

  1. Paint your door a light color.
  2. Select a core, such as honeycomb or steel-stiffened, that is less dense.
  3. Install an awning or canopy over the door, so the sun does not directly hit the door.
  4. Add landscaping to provide shade to the door.

Taking these steps can help reduce thermal bowing in your doors. LaForce is a solutions provider, and can assist you in finding the correct door and core for your facility which can reduce the risk of thermal bowing. Learn more about our services and fill out our contact form to get started on your next project today!