LYNN – The Friday morning fire that wrecked a popular sandwich shop and snarled traffic could prompt reforms in local building codes.Fire investigators need time to sort through the fire that damaged half of Superior Roast Beef before they can pinpoint the cause of the fire in the 200 Lynnfield St. takeout spot.Firefighters declared the blaze a working fire at 5:44 a.m. and struck a second alarm at 6:16 a.m. to ensure enough firefighters were on hand to fight the fire.A neighbor reported the fire at 5:30 a.m. and District Fire Chief William Curran said firefighters arrived to find the single-story building full of smoke.”There was a lot of heat in the ceiling. As soon as we put a hole in the roof it was burning like crazy,” Curran said.Firefighters found at least four layers of roofing, including an old set of garage doors and gaps between the layers that, Curran said, made it tough to fight the fire.”Normally we pull the ceiling down, expose the fire and put water on it. We couldn’t pull this from below or stand on it without risking falling into the fire,” Curran said.He said the current city building code does not require contractors or building owners to tear out an old ceiling or roof before adding a new one. He said fire officials may propose such a requirement to minimize risks faced by firefighters battling blazes in older buildings.”This is an economical way to renovate but it is really tough on the fire services,” he said.Firefighters confined the blaze to an older section of the Superior building and kept it from spreading to the addition added in 2006 and 2007.Owner James Roumeliotis took out a city building permit in July 2006 to do interior restaurant renovations, including new framing, a kitchen, bathroom and doors.He received a state fire permit to install a wet chemical fire system in September 2006 and a local certificate of fire inspection on March 27, 2007.Roumeliotis said the fire leaves seven employees without work. He vowed to rebuild and credited Lynn Area Chamber of Commerce members and others with offering him assistance Friday, just hours after the fire.”I’ll be open as soon as I can,” he said.