Can I run electrical along a furring strip in EMT?
flex metal requires the spacing.  PVC and EMT do not.

300.4(D) Cables and Raceways Parallel to Framing Members and Furring Strips. ... the cable or raceway shall be installed and supported so that the nearest outside surface of the cable or raceway is not less than 32 mm (1 1/4 in.) from the nearest edge of the framing member or furring strips where nails or screws are likely to penetrate. Where this distance cannot be maintained, the cable or raceway shall be protected from penetration by nails or screws by a steel plate, sleeve, or equivalent at least 1.6 mm (1/16 in.) thick.
Exception No.1: Steel plates, sleeves, or the equivalent shall not be required to protect rigid metal conduit, intermediate metal conduit, rigid nonmetallic conduit, or electrical metallic tubing.


Flex is not on the exception list.
EMT is on the exception list.
NEC is rather cryptic about what exactly it means by &quot;rigid nonmetallic conduit&quot;.  However the table at 392.10(a) says RNmC is controlled by Article 352, and Article 352 claims to govern PVC conduit. So it appears PVC does rate an exception.