“Is it OK to mix Crib 5 and Crib 3?” was the question. The client further explained that they planned to use a Crib 5 inter-liner and a Crib 3 fabric and was this OK in a restaurant?
I think the uncertainty existed as sometimes with domestic usage interlining can help with meeting FR needs.
However for non-residential spaces that is NOT the case.
The Crib5/Crib 3 mix would have been OK in an office type environment where Crib 3 was required however in a public space this is certainly not acceptable and so a different fabric is needed that is inherently Crib 5 or can be treated to Crib 5.