When using the W-L-1247 Fire Stop Detail is there a restriction on spacing the framed opening when they are side by side? The detail states the max opening is 32"x32" for a single multi penetration metal frame out. I have a contractor that is trying to put these side by side and separating them only with a single stud between them. Is this acceptable or is there a rule about spacing these multi-penetration firestops apart (stud bay)? To be clear this is for a 1HR and 2HR rated partition wall.
Hello Ronda,
Thank you for reaching out to the Fire Protection Design Team with your firestop question. As long as all the materials in the listed system can be installed properly and there is a structurally sound section of wall between both openings there is no minimum spacing, from a firestop standpoint, between to penetration systems. However, you should also always verify any additional requirements of applicable codes are met at the location. If it is necessary to combine all the penetrants pictured into one framed opening that exceeds the parameters of the listed system you can request an engineering judgement, which will be a custom firestop detail that matches that condition. You can do so by visiting hilti.com/ej.
Regards,
Ricardo Mejia