If I understand the problem correctly, You have a truss which was originally designed to span 10', now the span has changed to 12'. You want to use the existing truss, by adding 2' to it with some type of connection.
First, if this truss is the some type I am used to, wood 2x4, NE USA, they are...
If you find one let me know, I am still looking. See my question thread256-74708. With all those answers I still can not find a map showing the actual frost depth for specific locations.
I have dealt extensively with National Lumber in the Boston area with excelent results. I do not know how far they ship, you might call them and see if they have any local companies that they deal with. These days with CAD and email it really doesn't matter where they are.
I am trying to find some type of map which show the actual depth of frost for different areas, maybe a break down by county (USA). I am from Mass, the state building code states 4'-0" foundation depth accross the entire state. I am looking for something that would give some actual depth of...
The code that applies to the design of steel structures is the AISC code. Be aware of the fact that the stack is most likely hot, therefore reduced allowables should be considered. Allow for the thermal growth of the structural members.