Any common or party wall will be a firewall. A firewall shall consist of eight inch (8") masonry. If composition roofing is used, the firewall will extend through the roof decking. When a more flammable roofing is used, the firewall will extend twenty four inches (24") through the roof. There will not be any opening in a firewall. All wiring in a firewall will be in metal conduit and caulked at all openings. (2001 Code § 150.128)