The overlap between the fire door and the door frame shall not be less than 10mm, and the gap between the door and the door frame shall not be greater than 4mm. After the fire door is installed and closed, the gap should not be too large, otherwise the sealing performance of the fire door is difficult to guarantee, and it is difficult to reflect its function of suppressing the spread of fire and smoke under fire conditions.

https://ztfiredoor.com/20431.html

fire door emergenxy exit,fire proff doors,20 minute steel fire rated door,stainless fire rated door,flush fire rates doors,backyard fire door,fire door emergenxy exit,fire rated shutter door,20 minute steel fire rated door,fire proof security steel doors,flush fire rates doors,2 hour fire rated door price,20 minute steel fire rated door,security fire steel door,flush fire rates doors,fire door emergenxy exit