I have a floor plate with R2, S-2, and A-2. The aggregate area of S-2 and A-2 are over 10% of the floor plate. If I take the floor as un-separated occupancies, then I know I have to follow 20' dead end as A-2 is the more stringent. I am wondering if I separate A-2 from the rest of the floor with 1-hour fire barrier with 45 min. door, does it mean max. 50' dead end corridor for R-2 will apply or it's not the case unless aggregate area of S-2 and A-2 is under 10%?