A building I service has the same problem every afternoon: The doors become very difficult to open. What is the cause and what can I do to fix this problem for my customer?

The issue that you are experiencing is called thermal bow. The cause is the result of different temperature between in the inside and outside of the door which causes the core of the door to swell and the door to bow to the sunlight. There are a few recommendations on how the alleviate this condition:

  • Paint the door a lighter cool
  • Install an awning to limit the direct sunlight on the door
  • Install a door which the cores are less susceptible to thermal bow; either steel-stiffened core or honeycomb core are recommended

Also, is it suggested that a door with welded seamless edges will help limit the amount of thermal bow.


Do you have a question, or need a quote? Contact your local IDN Branch, or ask the Door Guy through our website.

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