Hello Richard, glad to hear you are enjoying the CQD. In general, the NEC®
does not prohibit the installation of NM Cable incapsulated in spray foam. There are rules pertaining to ampacity adjustment when cables are bundled in Section 310.15(C)(1). This becomes a manufacturer and product listing issue and the manufacturers of Type NM Cable do permit the cable to be encased in spray foam. This is a topic of concern that dates back to 1985, when testing was conducted by the University of Toronto on the potential overheating effects of Type NM-B Cable encased in spray foam. The findings were favorable showing maximum temperatures far below the 90º C rating of NM Cable insulation. This information can be reviewed in the NEMA Bulletin on the Thermal Effects of Residential-Installed Type NM-B Cable Encased in Spray Foam Insulation.