What are the specifications and purpose of the mounting timber used for barn doors? The mounting timber we use is 90mm x 18mm and is essential for providing the necessary support for both the tracks and the door. It is securely attached to the wall studs, ensuring stability and durability for the entire barn door system. For more details about the gap between the barn door and the wall, please refer to the “Why is there a gap between the barn door and the wall?” question in the “About the Barn Doors” section of our FAQs.