A few years back, we ran into a situation fastening steel roof decking down on an 18 degree pitch. We were working under AWS D1.3-89 code wich stated that an angle over 15 degrees was not in the flat position and therefore could not be puddle welded. We are in the same boat again, except the angle is 24 degrees. As an inspector, I am inclined to say the pitch is too great and it cannot be welded. The newer D1.3 sheetmetal welding code has changed wording that says "the sheet steel and substrate must be approximately flat". I am asking for your opinion as to what you consider approximately flat. The contractor considers it approximately flat and he has a compelling point. Any angle less than 45 degrees could be considered approximately flat because it is a lot closer to flat than vertical. Did they change this provision because of strong arguments that it could be safely welded at a slope? Your opinion of this matter will be greatly appreciated.