TG,
This Blocking is commonly used in the Interior walls. We call them "Cats" (Anyone know why?)
I've never heard of holes through them being an issue but am curious about the requirements for these. I did find something in the NYS Resi Code (which is a modified IRC) Electrical Section, but not sure what it means:
E3302.3 Penetration of firestops and draftstops. Penetrations through fire blocking and draftstopping shall be protected in an approved manner to maintain the integrity of the element penetrated.
Bill
[This message has been edited by Bill Addiss (edited 03-31-2003).]