- “UL listed” “UL fire rated” These terms are thrown around quite often when it comes to fire door accessories, but the truth is, just because a product makes these claims, does NOT mean it is “rated” or “listed” specifically for excessive clearances. To be an effective remedy for excessive clearances, any fire door accessory applied for this purpose must be UL listed or approved specifically for excessive clearances.
- All accessories are tested and listed according to the NFPA-252 standard; using 1/8 in. clearance on wood doors and 3/16 in. clearance on steel doors; the clearances allowed on a compliant fire door assembly by the NFPA-80. To be approved for excessive clearances, a product must be tested with excessive clearances.
- A fire door assembly is only as good as the lowest rated part on that assembly. Therefore, applying a 20-minute rated fire door accessory brings a 90-minute door down to a 20-minute rating. It will also bring down the rating of the fire separation wall the assembly is on.
- Aluminum products including smoke seal, sound seal, and weather stripping may be UL listed, but are not rated for excessive clearances over 20 minutes.
- The Crown Fire Door Stop System for wood doors is rated for up to 90 minutes with an excessive clearance of up to 3/8/in. The steel door system is rated for up to 180 minutes with an excessive clearance of 1/2 in. The Fire Door Extension is rated for up to 90 minutes with an excessive clearance of up to 2 inches.
--- All Products US Patent Nos. 9,151,106 & 9,518,422 | Canadian Patent Nos. 2846726 & 2939255 ---