Pratt Truss Roof Details

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Pratt truss roof details.

There are many types of roof trusses as wall as many types of roofs more types than there are parts. These can vary a lot. The roots of the pratt truss involved using iron not wood for the angled members. A way of making a larger truss out of pre fabricated elements of smaller trusses these roof trusses are simple in design but very effective and cheap to build.

In a conventional pratt truss diagonal members are in tension for gravity loads. Pratt trusses are commonly used in long span buildings ranging from 20 to 100 m in span. Fan truss it is made of steel. 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.

The roof truss structure and design is integral to roof structural integrity and shape. Pratt truss pratt truss is made of steel. Pratt truss this is one of the most popular steel roof truss types and it is quite economical. It used wood for the vertical members.

The ones in the photo above are in a heritage building of around the 1950 s fannie bay gaol darwin nt. It offers a new alternative in prefabrication and field assembly methods without basic departures from established. It can be used for spans from 6 10m. This article and series of illustrated diagrams shows you all the parts of a basic roof truss king truss and queen truss.

Better yet build your own pratt and howe truss bridges and compare their strength on your own. I think this does give the pratt an advantage but read my best bridge design article more for information. For further details on how the loads are calculated on a truss and other design details please read this. This type of truss is used where gravity loads are predominant see below left.

However with most model bridges you are just using wood. Vertical members are tension and diagonal members are compression. These are very economical form of roof trusses. The truss framed system tfs is a new light frame wood construction concept that inte grates customary construction components roof trusses floor trusses and wall studs into unitized frames.