Pratt Truss Roof

The design uses vertical members for compression and diagonal members to respond to tension.

Pratt truss roof.

It was designed by the thomas willis pratt 1812 1875 and his father caleb pratt a pair of american engineers just several years after william howe patented his famous howe truss design. Often seen in bridges it features several vertical chords that are connected by a diagonal chord. Pratt truss n truss pratt trusses are commonly used in long span buildings ranging from 20 to 100 m in span. The pratt steel roof truss design is one of the most common designs.

With a nod to several dramatic precedents this proposal literally joins the two properties by bridging them from side to side with an 85 foot pratt truss. Components of roof truss. Hayward building systems located in santa maria ca manufactures quality plated wood trusses for residential multi family and commercial projects. In a conventional pratt truss diagonal members are in tension for gravity loads.

Hayward uses only high quality lumber and precision automated saws and assembly equipment to produce roof trusses for any style and size of roofing system. The pratt truss design remained popular as bridge designers switched from wood to iron and from iron to steel. A roof truss is a structural unit designed to frame a roof and to support the roof material interior ceiling insulation and forces caused by snow rain and wind. A roof truss is supported by the exterior walls and span the width of the building.

The pratt truss was patented in 1844 by two boston railway engineers caleb pratt and his son thomas willis pratt. In this fashion they form a pattern of interconnected ns. Horizontal roof rafters. Interestingly their patent had less to do with design and more to do with a method for building trusses.

This type of truss is used where gravity loads are predominant see below left. This bridge design immediately became widely used during the period when many bridges moved from wood components toward all steel construction designs. This particular type of truss offers some interesting features mainly thanks to the fact that the vertical members provide tension while the diagonal ones are bringing in compression. Beams and columns deflection and stress moment of inertia section modulus and technical information of beams and columns.

Pratt truss this is one of the most popular steel roof truss types and it is quite economical.