请教关于Townhouse换Roofing, is FRT plywood a mandate?

I got mixed input from different roofer.

Did anyone apy to replace old plywood with FRT plywood to meet code? even the roof deck is in OK condition? 

For a re-roofing job for a townhouse without a firewall, is FRT (fire resistence treated) plywood replacement mandatory, when

1. just replace roof shingles, no plywood roof deck will be touched?

2. replace roof shingle with a few pieces of damp plywood roof deck?

Different roofer seem offering different explanation. I anticipate the FRT panle is mandatory for new townhouse roof when there is no firewall built in.

Does anyone replace townhouse roofing recently since the new building code update?

This regulation is for townhouse and condo roof only to prevent fire spread.

Thanks 

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