the history_evolution of roof trusses
TRANSCRIPT
THE HISTORY/EVOLUTIONOF ROOF TRUSSES
ROOF TRUSSES HAVE CHANGED QUITE A BITTHROUGHOUT THE YEARS WITH A VARIETY
OF DESIGNS OVER MANY DECADES.
TRUSS CONSTRUCTION HAS LONG BEENASSOCIATED WITH HIGH-ENDVERNACULAR CARPENTRY.
THE TRUSS FORM ORIGINALLY CAME OUTFROM THE TIMBER FRAMING METHODS OF
CLASSICAL ANTIQUITY IN THE MEDITERRANEAN REGION.
FROM THE MIDDLE AGES THROUGH THE RENAISSANCE,THERE WERE A VARIETY OF LONG-SPAN ROOF SYSTEMS
USED IN BUILDING DIFFERENT STRUCTURES.
EXCEPT FOR THE PANTHEON IN ROME,ALL ANCIENT TRUSS MEMBERS WERE MADE OUT
OF WOOD FOR NEARLY TWO MILLENNIA
UNTIL IRON AND STEEL ROOF FRAMESSTARTED BEING MADE AT THE END
OF THE 18TH CENTURY.
METAL WAS USED IN TRUSSESDATING BACK TO THE MIDDLE AGES,
THOUGH INCONSISTENTLY.
WROUGHT IRON STRAPS WITH FORELOCK BOLTSWERE USED TO REINFORCE TENSION JOINERY.
NEOCLASSICAL ARCHITECTURE FOR LARGE HALLS,ESPECIALLY IN THE AMERICANPOST-REVOLUTIONARY PERIOD
HAD A BIG INFLUENCEOF THE SIMPLIFICATION OF TRUSS DESIGN.
SIMPLIFICATION OF TRUSS DESIGNALSO CAME ABOUT FROM THE AVAILABILITY
OF LARGE, LONG TIMBER,
AS WELL AS THE RISING POPULARITY OF LONG-SPANWOOD TRUSS BRIDGE CONSTRUCTION AND NEW
TECHNOLOGY IN LATE 18TH CENTURY NORTH AMERICA.
TODAY, WOOD TRUSSES ARE STILL COMMONLY USEDTO BUILD A MULTITUDE OF STRUCTURES, INCLUDINGCHURCHES, BRIDGES, AND EVEN PRIVATE HOMES.