Has anyone got "engineering" approval for the kind of spans depicted in here
http://www.tfguild.org/publications/queenposttrussTF71.pdf50 - 60 ft clear span...some over 200 yrs old and still standing.
There are a lot of "approved" engineered structures that are NOT still standing.....not to mention the thousands of old barns around the country that have long survived the stick built house on the same property.
I wonder how long exactly a building structure/system has to stand before it can be considered "SAFE" or "acceptable".....
