“Just a small gap”

“Just a small gap…”

If you read the code references on this website, you may understand why some say, “It’s just a small gap!”

Exact standards exist and must be followed in order for a fire door assembly to function optimally. The frame and the door itself must be installed perfectly after being built to an exact size. The main problem exists in that the doors and frames are built to minimum standards; and perfect installation may never happen, but even if it did, buildings settle as years go by, creating more imperfection. The door is replaced, and if that actually fixes the problem, the cycle begins again. You can see why some would want to ignore the gaps!

But this issue is not only one of compliance, it directly affects how a fire door assembly will perform in a fire situation. An assembly with excessive gaps cannot hold back hot gases, fire, and smoke. In addition, when the hose stream pressure is applied by a firefighter, an assembly with excessive gaps will collapse. “Just a small gap” can provide oxygen to fuel the fire and compromise the effectiveness of a fire door assembly in minutes.

Now, the easy-to-install Crown Fire Door Stop System is the solution to these problems. The system extends the jamb on all three sides to eliminate excessive clearances, will support hose stream pressure as applied by the firefighter, as the door rests securely against the jamb, and will properly seal out hot gases, fire, and smoke. The Fire Door Extension is completely adjustable to correct excessive undercuts up to 2″, restoring fire doors to function as part of an overall fire protection system as intended.

In a fire test, doors will fail with “just a small gap.” This means, in an actual fire situation, property or even lives may be lost. It’s NOT “just a small gap!” And now it’s easy to fix!

--- All Products US Patent Nos. 9,151,106 & 9,518,422 | Canadian Patent Nos. 2,846,726 & 2,939,255 ---


The Crown Fire Door Stop System is UL approved for excessive clearances on wood and steel fire doors.The Crown Fire Door Extension has been UL approved to correct excessive undercuts on wood and steel fire doors. Applying these products does not increase or decrease the fire door assembly’s existing fire rating.

Crown is the ORIGINAL, UL-listed, 90-minute wood door solution and the ONLY 180-minute steel door solution for excessive clearances and gaps.