FOR YEARS, truss design engineers and municipalities have allowed gable end trusses to be placed next to a cathedral ceiling - in violation of building codes. Although those in the industry (i.e., municipalities, engineers, enforcement agencies at state and/or provincial level, professional journals, etc.) clearly knew there was a problem, no one seemed to see "the origin" of the problem. In my opinion, as a code tester and homeowner who has lived a nightmare over the past 4 years as a result of all of this, and as a person who sat next to a truss manufacturer to see how the truss design software works, I am of the very strong opinion that the root of the problems stems from truss design software that was clearly, in my opinion as a code tester, not properly tested - allowing potentially thousands of homes to go up with a major structural defect that made the roof and/or exterior load-bearing wall section next to such a cathedral ceiling subject to collapse!
By placing a gable end truss next to a cathedral ceiling, the truss design engineer (who should be held responsible for truss suitability) is CREATING a hinge in the wall below and making it subject to collapse. In a FLAT ceiling, the ceiling acts as a BRACE for the exterior wall. By placing the bottom chord of a gable end truss next to a cathedral ceiling, that BRACE IS GONE... and there is VIRTUALLY NOTHING BRACING THE EXTERIOR LOAD-BEARING WALL NEXT TO THE CATHEDRAL CEILING.
Determination of the PROPER truss has NOTHING to do with the house design itself because the PROPER TRUSS - a scissor type truss) would sit on the same two opposing walls as the other cathedral ceiling trusses - thus allowing for proper bracing since all scissor trusses would have the same bottom chord level and would allow for the truss in the exterior load bearing wall to be properly braced by not only allowing for proper lateral bracing via joining all bottom chords for the cathedral ceiling but also by allowing the truss in the load-bearing exterior wall to be included in the cathedral sheathing - thus providing for further bracing into the entire cathedral ceiling structure.
Homes with this problem require the involvement of an engineer since truss suitabiilty can ONLY be determined by an engineer!
To provide a gable end truss next to a cathedral ceiling violates NUMEROUS provisions of building codes and results in a MAJOR STRUCTURAL DEFECT - impacting lives and property. The industry and its regulators have known about this for years and in my opinion, have been hiding it from the public due to the massive liabilities that would surely come via claims as homeowners insist their homes be fixed to correct the problem.
Issue Explained In Structure Magazine in 2007
BOTTOM LINE- Do NOT put a gable end truss in an exterior load-bearing wall next to a cathedral ceiling...
Doing so will make the roof and/or wall subject to collapse!
Cathedral Ceiling Calamity - The Exposing Of A Potentially Massive Building Scandal
In The Wood Truss Industry!!!