Interleafing of FA speaker circuits

[mshields]

We call for interleafing of speaker circuits in our specifications on each floor of a high rise. I'm wondering if this is a code requirement or just a good practice. And regardless, should we do it in stairwells.

Since stairwells are not evacuation zones, I'm thinking that it's not necessary but obviously can't hurt.

What say you?

 

[iwire]

Mike in my experience that is a Boston standard, not sure if it is code but it is enforced.

We also have to alternate strobe circuits when more than one is in the same area. (A corridor for instance)

 

[hmp1313]

Fire Alarm in Baltimore is also done the sameway. Stairwells are a debatable issue but most inspectors require.