# Cutting the bottom of a fire-rated door



## jar546 (Jan 17, 2020)

If a fire rated door must be cut to make room for new, much higher tile, can it be legally done?

Would a letter from the manufacturer's engineer suffice or would testing be required?


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## cda (Jan 17, 2020)

From the "la puerta" guru



NFPA 80 specifically allows the following preparations to be made on the job site:


Holes for surface-applied hardware
Function holes for mortise locks
Holes for labeled viewers
A maximum 3/4-inch undercutting of wood and composite doors (verify this with the door manufacturer before modifying the door)
Installation of protection plates

https://idighardware.com/2018/12/qq-job-site-preps-for-fire-doors/


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## ADAguy (Jan 21, 2020)

Good one, thank you


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