6
Metal building materials; transportable buildings of metal; frameworks of metal; stairs and steps of common metal; metal ducting; walkways of common metal; metal railings, protective railings of metal; goods of metal for use in rooftop support systems; small items of metal hardware; pipes and tubes of metal
17
Goods made from rubber; plastics for use in building materials, plastics for use in rooftop support systems; stopping and insulating materials; flexible non-metallic pipes
19
Non-metallic building materials; non-metallic rigid pipes for building; frameworks for use in building (non-metallic); non-metallic walkways; non-metallic stairs and steps; non-metallic ducting; non-metallic railings, non-metallic protective railings; non-metallic goods for use in rooftop support systems; asphalt, pitch and bitumen; non-metallic transportable buildings